Electrode for all-solid-state battery and all-solid-state battery

Abstract

The present invention suppresses corrosion of a current collector and prevents any increase in the resistance of an electrode in an all-solid battery in which an electrode that contains a sulfide-based solid electrolyte is used.　An electrode for an all-solid-state battery according to the present invention has a mixture containing an active material and a sulfide-based solid electrolyte, and a current collector. The current collector is configured from an alloy containing Ni and Cr. The Ni content in the alloy is 60 mass% or greater, and the Cr content in the alloy is 0.1-40 mass%. The all-solid-state battery according to the present invention is characterized by having a positive electrode, a negative electrode, and a solid electrolyte layer, and is characterized in that at least one of the positive electrode and the negative electrode is the electrode for an all-solid-state battery according to the present invention.

Description

Electrode for all-solid-state battery and all-solid-state battery

[0001] The present invention relates to an electrode for an all-solid-state battery that can be used to assemble an all-solid-state battery, and an all-solid-state battery using the electrode.

[0002] In recent years, with the development of portable electronic devices such as mobile phones and laptop personal computers, and the practical application of electric vehicles, there has been a growing demand for small, lightweight batteries with high capacity and high energy density.

[0003] Currently, lithium batteries, especially lithium ion batteries, that can meet this requirement use lithium cobalt oxide (LiCoO ２ ), lithium nickel oxide (LiNiO ２ ), graphite or the like is used as the negative electrode active material, and an organic electrolyte solution containing an organic solvent and a lithium salt is used as the non-aqueous electrolyte.

[0004] Furthermore, with the further development of devices to which lithium-ion batteries are applied, there is a demand for lithium-ion batteries with longer life, higher capacity, and higher energy density, as well as a high demand for the reliability of lithium-ion secondary batteries with longer life, higher capacity, and higher energy density.

[0005] However, the organic electrolyte used in lithium-ion batteries contains flammable organic solvents, which can cause the organic electrolyte to generate excessive heat in the event of an abnormality such as a short circuit. Furthermore, with the recent trend toward higher energy density in lithium-ion batteries and an increasing amount of organic solvent in the organic electrolyte, there is a growing demand for greater reliability in lithium-ion batteries.

[0006] In light of the above, all-solid-state lithium batteries (all-solid-state batteries) that do not use organic solvents are also being considered. All-solid-state lithium batteries use sheets or molded bodies of solid electrolytes that do not use organic solvents instead of conventional organic solvent-based electrolytes, and are highly reliable without the risk of abnormal heat generation by the solid electrolyte.

[0007] As the solid electrolyte, sulfide-based solid electrolytes, hydride-based solid electrolytes, halide-based solid electrolytes, oxide-based solid electrolytes, and the like have been investigated. Among these, the development of sulfide-based solid electrolytes has progressed rapidly due to their high lithium ion conductivity, and an all-solid-state battery using a sulfide-based solid electrolyte in each of the positive electrode, negative electrode, and solid electrolyte layer has also been proposed (Patent Document 1).

[0008] However, because sulfide-based solid electrolytes are highly reactive, it was discovered that when they are used in electrodes, they can react with the solid electrolyte depending on the material of the current collector during repeated charge and discharge, resulting in increased resistance at the interface.

[0009] In response to this, Patent Document 2 discloses a current collector for an all-solid-state battery in which a coating layer containing a powdered carbon material, acid-modified polyvinylidene fluoride, and poly-N-vinylpyrrolidone is formed on the surface of a sheet-like conductive substrate, and it is proposed that the coating layer enhances the corrosion resistance of the current collector.

[0010] Furthermore, Patent Documents 3 and 4 propose porous bodies made of an alloy of Ni and Cr and porous bodies made of an alloy of Ni, Cr, and Sn as metal porous bodies that can be used for applications such as current collectors for lithium ion secondary batteries, capacitors, fuel cells, and the like, various filters, and catalyst carriers.

[0011] JP 2023-022836 A JP 2020-198275 A JP 2012-149282 A JP 2014-065955 A

[0012] An object of the present invention is to suppress corrosion of a current collector and prevent an increase in the resistance of an electrode in an all-solid-state battery using an electrode containing a sulfide-based solid electrolyte.

[0013] The electrode for an all-solid-state battery of the present invention comprises a mixture containing an active material and a sulfide-based solid electrolyte, and a current collector, wherein the current collector is made of an alloy containing Ni and Cr, the Ni content of the alloy being 60 mass% or more, and the Cr content of the alloy being 0.1 mass% or more and 40 mass% or less.

[0014] The all-solid-state battery of the present invention has a positive electrode, a negative electrode, and a solid electrolyte layer, and at least one of the positive electrode and the negative electrode is the electrode for the all-solid-state battery of the present invention.

[0015] According to the present invention, it is possible to provide an electrode for an all-solid-state battery that contains a sulfide-based solid electrolyte and can suppress corrosion of a current collector, thereby suppressing an increase in resistance, and an all-solid-state battery that has the electrode and can suppress an increase in internal resistance.

[0016] Fig. 2 is a scanning electron microscope photograph for explaining the surface state of the electrode for the all-solid-state battery of the present invention. Fig. 3 is a cross-sectional view schematically showing an example of the all-solid-state battery of the present invention. Fig. 4 is a perspective view of a concave container of the all-solid-state battery of Fig. 2. Fig. 5 is a perspective view of an elastic conductive member of the all-solid-state battery of Fig. 2.

[0017] <Electrode for All-Solid-State Battery> The electrode for an all-solid-state battery of the present invention (hereinafter, sometimes simply referred to as "electrode") includes a mixture containing an active material and a sulfide-based solid electrolyte, and a current collector. The current collector is made of an alloy containing Ni (nickel) and Cr (chromium) (hereinafter, sometimes referred to as "Ni-Cr alloy"), in which the Ni content in the alloy is 60 mass % or more and the Cr content in the alloy is 0.1 mass % or more and 40 mass % or less.

[0018] Because Ni has high conductivity, using a current collector made of it reduces the resistance of the electrode and enables good collection of electricity generated from the mixture. However, if the electrode mixture contains a sulfide-based solid electrolyte, the current collector may corrode due to contact with the sulfide-based solid electrolyte, or sulfide gases such as hydrogen sulfide may be generated in a battery containing this electrode, causing corrosion of the current collector.

[0019] Therefore, in the electrode of the present invention, a current collector made of an alloy containing Ni and Cr is used, and the action of Cr in the current collector can suppress corrosion due to contact with the sulfide-based solid electrolyte or gas derived from the sulfide-based solid electrolyte.

[0020] However, in a current collector made of an alloy containing Ni and Cr, Cr also acts to reduce the conductivity of the current collector and increase the resistance of the electrode.

[0021] Therefore, in the electrode of the present invention, the Ni content and the Cr content in the Ni-Cr alloy constituting the current collector are each set within a specific range, thereby enabling good conductivity and suppressing corrosion by the sulfide-based solid electrolyte, thereby reducing the initial resistance and suppressing an increase in resistance due to corrosion.

[0022] As a result, in an all-solid-state battery using the electrode of the present invention (all-solid-state battery of the present invention), the internal resistance can be reduced and an increase in the internal resistance during use or storage can be effectively suppressed.

[0023] The electrode of the present invention can be used for at least one of the positive electrode and negative electrode of a secondary battery (all-solid-state secondary battery), and can also be used for at least one of the positive electrode and negative electrode of a primary battery (all-solid-state primary battery).

[0024] The electrode has a mixture containing an active material and a sulfide-based solid electrolyte, and a current collector, and has a structure in which, for example, a layer formed by the mixture, i.e., a mixture layer, is provided on one or both sides of the current collector. Alternatively, when the current collector is porous, the electrode can have a structure in which at least a portion of the mixture layer penetrates into the pores of the current collector and is integrated therewith.

[0025] When the electrode is a positive electrode of an all-solid-state battery, the mixture (positive electrode mixture) contains a positive electrode active material and a sulfide-based solid electrolyte.

[0026] When the electrode is a positive electrode of an all-solid-state primary battery, the positive electrode active material can be the same as the positive electrode active material used in conventionally known non-aqueous electrolyte primary batteries. Specifically, for example, manganese dioxide, lithium-containing manganese oxide (e.g., LiMn ３ O ６or a composite oxide having the same crystal structure as manganese dioxide (e.g., β-type, γ-type, or a mixed structure of β-type and γ-type) and a Li content of 3.5% by mass or less, preferably 2% by mass or less, more preferably 1.5% by mass or less, particularly preferably 1% by mass or less); ａ Ti ５／３ O ４ (4 / 3≦a<7 / 3) and other lithium-containing composite oxides; vanadium oxide; niobium oxide; titanium oxide; sulfides such as iron disulfide; graphite fluoride; Ag ２ Silver sulfides such as S; NiO ２ Nickel oxides such as:

[0027] When the electrode is a positive electrode of an all-solid-state secondary battery, the positive electrode active material can be the same as the positive electrode active material used in conventionally known non-aqueous electrolyte secondary batteries. １－ｘ M ｒ Mn ２－ｒ O ４ (wherein M is at least one element selected from the group consisting of Li, Na, K, B, Mg, Ca, Sr, Ba, Ti, V, Cr, Zr, Fe, Co, Ni, Cu, Zn, Al, Sn, Sb, In, Nb, Ta, Mo, W, Y, Ru, and Rh, and 0≦x≦1, 0≦r≦1), a spinel-type lithium manganese composite oxide represented by Li ｒ Mn （１－ｓ－ｔ） Ni ｓ M ｔ O （２－ｕ） F ｖ (wherein M is at least one element selected from the group consisting of Co, Mg, Al, B, Ti, V, Cr, Fe, Cu, Zn, Zr, Mo, Sn, Ca, Sr, and W, and 0≦r≦1.2, 0<s<0.5, 0≦t≦0.5, u+v<1, −0.1≦u≦0.2, 0≦v≦0.1), a layered compound represented by １－ｘ Co １－ｒ M ｒ O ２(wherein M is at least one element selected from the group consisting of Al, Mg, Ti, V, Cr, Zr, Fe, Ni, Cu, Zn, Ga, Ge, Nb, Mo, Sn, Sb, and Ba, and 0≦x≦1, 0≦r≦0.5), lithium cobalt composite oxide represented by Li １－ｘ Ni １－ｒ M ｒ O ２ (wherein M is at least one element selected from the group consisting of Al, Mg, Ti, Zr, Fe, Co, Cu, Zn, Ga, Ge, Nb, Mo, Sn, Sb, and Ba, and 0≦x≦1, 0≦r≦0.5), lithium nickel composite oxide represented by Li １＋ｓ－ｘ M １－ｒ N ｒ P.O. ４ F ｓ (wherein M is at least one element selected from the group consisting of Fe, Mn, and Co, and N is at least one element selected from the group consisting of Al, Mg, Ti, Zr, Ni, Cu, Zn, Ga, Ge, Nb, Mo, Sn, Sb, V, and Ba, and 0≦x≦1, 0≦r≦0.5, 0≦s≦1), Li ２－ｘ M １－ｒ N ｒ P ２ O ７ (wherein M is at least one element selected from the group consisting of Fe, Mn, and Co, and N is at least one element selected from the group consisting of Al, Mg, Ti, Zr, Ni, Cu, Zn, Ga, Ge, Nb, Mo, Sn, Sb, V, and Ba, and 0≦x≦2, 0≦r≦0.5), and the like can be exemplified by pyrophosphate compounds represented by the formula (I) (wherein M is at least one element selected from the group consisting of Fe, Mn, and Co, and N is at least one element selected from the group consisting of Al, Mg, Ti, Zr, Ni, Cu, Zn, Ga, Ge, Nb, Mo, Sn, Sb, V, and Ba, and 0≦x≦2, 0≦r≦0.5), and only one of these may be used, or two or more may be used in combination.

[0028] When the electrode is a positive electrode of an all-solid-state secondary battery, the average particle size of the positive electrode active material is preferably 1 μm or more, more preferably 2 μm or more, and preferably 10 μm or less, more preferably 8 μm or less. The positive electrode active material may be primary particles or secondary particles formed by aggregation of primary particles. When a positive electrode active material having an average particle size within the above range is used, a large interface with the solid electrolyte contained in the positive electrode can be secured, thereby further improving the output characteristics of the battery.

[0029] The average particle diameter of various particles (positive electrode active material, solid electrolyte, etc.) referred to in this specification is the 50% diameter value (D) in the volume-based integrated fraction when the integrated volume is calculated from particles with small particle sizes using a particle size distribution measuring device (e.g., a Microtrac particle size distribution measuring device "HRA9320" manufactured by Nikkiso Co., Ltd.). ５０ ) means

[0030] When the electrode is a positive electrode of an all-solid-state secondary battery, the positive electrode active material preferably has a reaction suppression layer on its surface for suppressing reaction with the solid electrolyte contained in the electrode.

[0031] If the positive electrode active material and the solid electrolyte come into direct contact in the mixture layer (positive electrode mixture layer), the solid electrolyte may oxidize to form a resistance layer, which may reduce ionic conductivity in the positive electrode mixture layer. By providing a reaction suppression layer that suppresses reaction with the solid electrolyte on the surface of the positive electrode active material and preventing direct contact between the positive electrode active material and the solid electrolyte, it is possible to suppress a reduction in ionic conductivity in the positive electrode mixture layer due to oxidation of the solid electrolyte.

[0032] The reaction suppression layer may be made of a material that has ion conductivity and can suppress the reaction between the positive electrode active material and the solid electrolyte. Examples of materials that can form the reaction suppression layer include oxides containing Li and at least one element selected from the group consisting of Nb, P, B, Si, Ge, Ti, and Zr, more specifically, LiNbO ３ Nb-containing oxides such as Li ３ P.O. ４ , Li ３ BO ３ , Li ２ SO ４ , Li ４ SiO ４ , Li ４ GeO ４ , LiTiO ３ , LiZrO ３ , Li ２ WO ４The reaction suppression layer may contain only one of these oxides, or may contain two or more of them, or may contain a composite compound of two or more of these oxides. Among these oxides, it is preferable to use an Nb-containing oxide, such as LiNbO ３ It is more preferable to use

[0033] The reaction suppression layer is preferably present on the surface in an amount of 0.1 to 1.0 part by mass per 100 parts by mass of the positive electrode active material, which allows for effective suppression of the reaction between the positive electrode active material and the solid electrolyte.

[0034] Examples of methods for forming a reaction suppression layer on the surface of a positive electrode active material include the sol-gel method, mechanofusion method, CVD method, PVD method, and ALD method.

[0035] The content of the positive electrode active material in the positive electrode mixture is preferably 60 to 85 mass % from the viewpoint of increasing the energy density of an all-solid-state battery in which the electrode is used as a positive electrode.

[0036] The positive electrode mixture may contain a conductive additive. Specific examples thereof include carbon materials such as graphite (natural graphite, artificial graphite), graphene, carbon black, carbon nanofibers, and carbon nanotubes. ２ When S is used, conductive Ag is generated during the discharge reaction, so the conductive additive does not need to be contained. When the conductive additive is contained in the positive electrode mixture, the content thereof is preferably 1.0 part by mass or more, preferably 7.0 parts by mass or less, and more preferably 6.5 parts by mass or less, relative to 100 parts by mass of the positive electrode active material.

[0037] The positive electrode mixture may contain a binder. Specific examples include fluororesins such as polyvinylidene fluoride (PVDF). The positive electrode mixture contains a sulfide-based solid electrolyte. However, if the sulfide-based solid electrolyte ensures good formability in forming the positive electrode mixture layer without using a binder, the positive electrode mixture need not contain a binder.

[0038] When a binder is required in the positive electrode mixture, the content thereof is preferably 15% by mass or less, and preferably 0.5% by mass or more. On the other hand, when moldability can be obtained without the binder in the positive electrode mixture, the content thereof is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, and even more preferably 0% by mass (i.e., no binder is contained).

[0039] The positive electrode mixture contains a sulfide-based solid electrolyte. The sulfide-based solid electrolyte is Li ２ S-P ２ S ５ , Li ２ S-SiS ２ , Li ２ S-P ２ S ５ -GeS ２ , Li ２ S-B ２ S ３ In addition to particles of glass, thio-LISICON type particles [Li １０ GeP ２ S １２ , Li ９．５４ Si １．７４ P １．４４ S １１．７ Cl ０．３ The general formula Li12-12a-b+c+6d-eM is exemplified by １ ３＋ａ－ｂ－ｃ－ｄ M ２ ｂ M ３ ｃ M ４ ｄ M ５ １２－ｅ X ｅ (However, M １ is Si, Ge or Sn, M ２ is P or V, M ３ is Al, Ga, Y or Sb, M ４ is Zn, Ca, or Ba, M ５is either S or S and O, and X is F, Cl, Br or I; 0≦a<3, 0≦b+c+d≦3, 0≦e≦3)] or one having an argyrodite-type crystal structure (argyrodite-type solid electrolyte) can also be used.

[0040] Among these solid electrolytes, sulfide-based solid electrolytes containing Li and P are more preferred because of their high lithium ion conductivity, and argyrodite-type solid electrolytes are even more preferred because of their higher lithium ion conductivity and high chemical stability.

[0041] Examples of the argyrodite-type crystalline solid electrolyte include Li ６ P.S. ５ Particularly preferred are those represented by the following general composition formula (1), (2) or (3), such as Cl.

[0042] Li ７－ｋ P.S. ６－ｋ X ｋ (1)

[0043] In the general composition formula (1), X represents one or more halogen elements, and k satisfies 0.2<k<2.0.

[0044] Li ７－ｘ＋ｙ P.S. ６－ｘ Cl ｘ＋ｙ (2)

[0045] In the general composition formula (2), 0.05≦y≦0.9 and −3.0x+1.8≦y≦−3.0x+5.7.

[0046] Li ７－ａ P.S. ６－ａ Cl ｂ Br ｃ (3)

[0047] In the general composition formula (3), a=b+c, ​​0<a≦1.8, and 0.1≦b / c≦10.0.

[0048] The positive electrode mixture may contain other solid electrolytes together with the sulfide-based solid electrolyte. Examples of the solid electrolytes that may be contained in the positive electrode mixture together with the sulfide-based solid electrolyte include hydride-based solid electrolytes, halide-based solid electrolytes, and oxide-based solid electrolytes.

[0049] Examples of hydride-based solid electrolytes include LiBH ４ , LiBH ４ and a solid solution of the following alkali metal compound (e.g., LiBH ４ and the alkali metal compound in a molar ratio of 1:1 to 20:1. The alkali metal compound in the solid solution may be at least one selected from the group consisting of lithium halides (LiI, LiBr, LiF, LiCl, etc.), rubidium halides (RbI, RbBr, RbF, RbCl, etc.), cesium halides (CsI, CsBr, CsF, CsCl, etc.), lithium amide, rubidium amide, and cesium amide.

[0050] Examples of halide-based solid electrolytes include monoclinic LiAlCl ４ , defect spinel type or layer structure LiInBr ４ , monoclinic Li ６－３ｍ Y ｍ X ６ (wherein 0 < m < 2 and X = Cl or Br), and other known compounds described in, for example, WO 2020 / 070958 and WO 2020 / 070955 can also be used.

[0051] As the oxide-based solid electrolyte, for example, garnet-type Li ７ La ３ Zr ２ O １２ , NASICON type Li １＋Ｏ Al １＋Ｏ Ti ２－Ｏ (P.O. ４ ) ３ , Li １＋ｐ Al １＋ｐ Ge ２－ｐ (P.O. ４ ) ３ , perovskite-type Li ３ｑLa ２／３－ｑ TiO ３ Examples include:

[0052] The average particle size of the solid electrolyte is preferably 0.1 μm or more, and more preferably 0.2 μm or more, from the viewpoint of reducing grain boundary resistance, while it is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 1 μm or less, from the viewpoint of forming a sufficient contact interface between the active material and the solid electrolyte.

[0053] From the viewpoint of further increasing ionic conductivity in the positive electrode and further improving the output characteristics of the all-solid-state battery, the content of the solid electrolyte in the positive electrode mixture is preferably 10 parts by mass or more, and more preferably 15 parts by mass or more, when the content of the positive electrode active material is 100 parts by mass. However, if the amount of solid electrolyte in the positive electrode mixture is too large, the amounts of other components may be reduced, and the effects of these components may be reduced. Therefore, the content of solid electrolyte in the positive electrode mixture is preferably 65 parts by mass or less, and more preferably 60 parts by mass or less, when the content of the positive electrode active material is 100 parts by mass.

[0054] Furthermore, when the positive electrode mixture contains a sulfide-based solid electrolyte and another solid electrolyte, the content of the sulfide-based solid electrolyte in the total content of the solid electrolytes in the positive electrode mixture is preferably 20 mass % or more, more preferably 70 mass % or more, and may be 100 mass %.

[0055] When the electrode is a negative electrode of an all-solid-state battery, the mixture (negative electrode mixture) contains a negative electrode active material and a sulfide-based solid electrolyte.

[0056] Examples of the negative electrode active material include carbon materials such as graphite, lithium titanium oxides (lithium titanate, etc.), simple substances containing elements such as Si and Sn, compounds (oxides, etc.), and alloys thereof. Lithium metal and lithium alloys (lithium-aluminum alloys, lithium-indium alloys, etc.) can also be used as the negative electrode active material.

[0057] The content of the negative electrode active material in the negative electrode mixture is preferably 40 to 80 mass % from the viewpoint of increasing the energy density of an all-solid-state battery in which the electrode is used as a negative electrode.

[0058] The negative electrode mixture may contain a conductive additive. Specific examples include the same conductive additives as those exemplified above as the conductive additives that may be contained in the positive electrode mixture. The content of the conductive additive in the negative electrode mixture is preferably 10 to 30 parts by mass, relative to 100 parts by mass of the negative electrode active material.

[0059] The negative electrode mixture may contain a binder. Specific examples thereof include the same binders as those exemplified above as binders that may be contained in the positive electrode mixture. Although the negative electrode mixture contains a sulfide-based solid electrolyte, if the sulfide-based solid electrolyte can ensure good formability in forming the mixture layer (negative electrode mixture layer) without using a binder, the negative electrode mixture may not contain a binder.

[0060] When a binder is required in the negative electrode mixture, the content thereof is preferably 15% by mass or less, and preferably 0.5% by mass or more. On the other hand, when moldability can be obtained without the binder in the negative electrode mixture, the content thereof is preferably 0.5% by mass or less, more preferably 0.3% by mass or less, and even more preferably 0% by mass (i.e., no binder is contained).

[0061] The negative electrode mixture contains a sulfide-based solid electrolyte. Specific examples thereof include the same sulfide-based solid electrolytes as those exemplified above as those that can be contained in the positive electrode mixture. Among the sulfide-based solid electrolytes exemplified above, sulfide-based solid electrolytes containing Li and P are preferred because of their high lithium ion conductivity, and argyrodite-type solid electrolytes are more preferred because of their higher lithium ion conductivity and chemical stability, and those represented by the general composition formula (1), the general composition formula (2), or the general composition formula (3) are even more preferred.

[0062] The negative electrode mixture may contain other solid electrolytes together with the sulfide-based solid electrolyte. Examples of solid electrolytes that can be contained in the negative electrode mixture together with the sulfide-based solid electrolyte include the same hydride-based solid electrolytes, halide-based solid electrolytes, and oxide-based solid electrolytes as those exemplified above as those that can be contained in the positive electrode mixture.

[0063] For the same reasons as in the case of the positive electrode mixture, the average particle size of the solid electrolyte in the negative electrode mixture is preferably 0.1 μm or more, more preferably 0.2 μm or more, and is preferably 10 μm or less, more preferably 5 μm or less.

[0064] From the viewpoint of further increasing ionic conductivity in the negative electrode and further improving the output characteristics of the all-solid-state battery, the content of the solid electrolyte in the negative electrode mixture is preferably 30 parts by mass or more, and more preferably 35 parts by mass or more, when the content of the negative electrode active material is 100 parts by mass. However, if the amount of solid electrolyte in the negative electrode mixture is too large, the amounts of other components may be reduced, and the effects of these components may be reduced. Therefore, the content of solid electrolyte in the negative electrode mixture is preferably 130 parts by mass or less, and more preferably 110 parts by mass or less, when the content of the negative electrode active material is 100 parts by mass.

[0065] Furthermore, when the negative electrode mixture contains a sulfide-based solid electrolyte and another solid electrolyte, the content of the sulfide-based solid electrolyte in the total content of the solid electrolytes in the negative electrode mixture is preferably 20 mass % or more, more preferably 70 mass % or more, and may be 100 mass %.

[0066] The thickness of the mixture in the electrode (thickness of the mixture layer) is preferably 0.2 mm or more, more preferably 0.5 mm or more, and even more preferably 0.7 mm or more, while it is preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1.5 mm or less.

[0067] The electrode has a current collector made of an alloy containing Ni and Cr, and the Ni content in the alloy is 60% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more, from the viewpoint of improving the conductivity of the current collector and reducing the resistance of the electrode.

[0068] The Cr content in the alloy is 0.1% by mass or more, preferably 3% by mass or more, and more preferably 10% by mass or more, from the viewpoint of suppressing corrosion of the current collector due to reaction with the sulfide-based solid electrolyte and reaction with gas generated from the sulfide-based solid electrolyte, and suppressing an increase in electrode resistance over time. However, if the Cr content in the alloy is too high, the conductivity of the current collector may decrease, resulting in an increase in electrode resistance. Therefore, the Cr content in the alloy is 40% by mass or less, preferably 30% by mass or less, and more preferably 20% by mass or less.

[0069] As can be seen from the Ni content and Cr content in the alloy constituting the current collector, the composition of the alloy constituting the current collector typically contains Cr in the above-mentioned content, with the remainder being Ni, but it may also contain, for example, elements other than Ni and Cr (e.g., Sn, Fe, Co, Ti, Al, Mo, etc.) in a total content of 39.9 mass% or less. That is, the composition of the alloy constituting the current collector may contain the total content of Ni and Cr of 60.1 mass% or more and elements other than Ni and Cr in a range of 39.9 mass% or less.

[0070] The current collector can be a foil made of the alloy, or a porous metal substrate such as a punched metal, a mesh, an expanded metal, or a foamed metal. The thickness of the current collector varies depending on the type, but is preferably 10 μm or more for foil, preferably 50 μm or more for punched metal, a mesh, or an expanded metal, and preferably 100 μm or more for foamed metal substrates such as foamed metal. The thickness of the current collector is preferably 50 μm or less for foil, preferably 300 μm or less for punched metal, a mesh, or an expanded metal, and preferably 3000 μm or less for foamed metal substrates such as foamed metal.

[0071] Among these current collectors, it is preferable to use a porous metal substrate because of its higher current collection efficiency, and it is more preferable to use a foamed metal substrate (such as "Celmet (registered trademark)" manufactured by Sumitomo Electric Industries, Ltd.). When the current collector is made of a porous metal substrate, at least a portion of the mixture (mixture layer) penetrates into the pores, thereby improving the adhesion between the current collector and the mixture. Furthermore, when the current collector is a foamed metal substrate, the contact area between the current collector and the mixture layer becomes larger, making it possible to further reduce the resistance of the electrode.

[0072] That is, the electrode preferably has a foam metal substrate as a current collector, and at least a portion of the mixture is filled into the pores of the foam metal substrate. More specifically, it is preferable that at least a portion of the foam metal substrate serving as the current collector of the electrode, including the end portion on the mixture layer side, is embedded in the surface layer of the mixture layer and is integrated with the mixture layer.

[0073] In addition, such a foamed metal substrate is usually compressed and reduced in thickness when producing an electrode together with a composite, so that the thickness before use in the electrode is greater than the thickness in the electrode. For example, the thickness of the foamed metal substrate before compression is preferably 0.1 mm or more, more preferably 0.3 mm or more, and particularly preferably 0.5 mm or more, while preferably 3 mm or less, more preferably 2 mm or less, and particularly preferably 1.5 mm or less. For example, in the method for producing an electrode laminate described below, the foamed metal substrate is compressed in the thickness direction when an electrode is produced through a step of pressing the composite and the metal substrate, and its thickness becomes the value described below.

[0074] The porosity of the foam metal substrate before compression is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more, so that the pores of the metal substrate can be easily filled with the composite material and the metal substrate and the composite material layer can be easily integrated in the process of pressurizing the foam metal substrate and the composite material. On the other hand, in order to increase the volume of the foam metal substrate by a certain amount or more and to increase the conductivity, the porosity is preferably 99.5% or less, more preferably 99% or less, and even more preferably 98.5% or less.

[0075] In addition, the porous metal substrate (particularly the foamed metal substrate) has a basis weight of 600 g / m from the viewpoint of adjusting the porosity within a suitable range. ２ Preferably, the weight is 400 g / m or less. ２ If the basis weight of the porous metal substrate (particularly the foamed metal substrate) is too small, the resistance of the current collector increases. ２ It is preferable that the weight is 300 g / m or more. ２ More preferably, it is equal to or greater than this.

[0076] The density of the foamed metal substrate (apparent density calculated including the volume of pores) is 0.22 g / cm for the same reason as above. ３ It is preferable that the density is 0.66 g / cm or more. ３ It is preferable that:

[0077] Furthermore, in the case of an electrode having a foam metal substrate as a current collector, in which at least a portion of the metal substrate, including the end portion on the mix layer side, is embedded in the surface layer portion of the mix layer and integrated with the mix layer, the thickness of the portion of the foam metal substrate embedded in the mix layer is preferably 10% or more, and more preferably 20% or more, of the thickness of the metal substrate (the thickness of the entire foam metal substrate, including the thickness of the portion where the mix layer coexists; unless otherwise specified, the same applies hereinafter to the thickness of the foam metal substrate), from the viewpoint of more reliably integrating the metal substrate and the mix layer.

[0078] In an electrode having a foam metal substrate as a current collector, at least a portion of the metal substrate, including the end portion on the mix layer side, is embedded in the surface layer of the mix layer and integrated with the mix layer. To reduce the resistance when contacting the conductive path (described in detail below) in the exterior of an all-solid-state battery, it is desirable that the end portion of the foam metal substrate opposite the mix layer side (hereinafter sometimes referred to as the surface end portion) is not embedded in the mix layer, and the end portion (surface of the electrode) of the electrode is composed only of the metal substrate. That is, for example, in the manufacturing method of an electrode laminate described below, when manufacturing an electrode through a process of pressing the mix and the foam metal substrate, it is desirable that the metal substrate is compressed in the thickness direction, and the pores at the surface end portion of the metal substrate are crushed and eliminated, leaving only the metal substrate exposed on the surface of the electrode. However, some of the pores at the surface end portion of the foam metal substrate may not be crushed and may remain as pores or may be filled with the mix. It is also acceptable that a portion of the mix, together with the surface end portion of the metal substrate, is exposed on the surface of the electrode, as long as it does not significantly affect the contact resistance with the conductive path. In other words, as long as the surface side end of the foam metal substrate can be exposed to the electrode surface, the entire metal substrate (100% of the thickness of the foam metal substrate) may be embedded in the surface layer of the mixture layer. By filling the pores of the foam metal substrate with the mixture up to the surface of the electrode, the integration of the mixture and the metal substrate can be more reliably achieved.

[0079] Fig. 1 shows a scanning electron microscope (SEM) photograph for explaining the surface state of an electrode having a foam metal substrate as a current collector (note that the SEM photograph shown in Fig. 1 is not a photograph of the surface of the electrode of the present invention, but a photograph of an electrode having a surface state similar to that of the electrode of the present invention (an electrode corresponding to Comparative Example 1 described below), and is shown only for the purpose of explaining the surface state of the electrode of the present invention). On the surface of the electrode shown in Fig. 1, the end of the foam metal substrate 122 of the electrode is exposed, and part of the mixture 121a is also exposed on the surface of the electrode by entering pores present at the end of the metal substrate.

[0080] However, since the contact resistance between the foamed metal substrate and the conductive path of the all-solid-state battery increases as the proportion (area ratio) of the mixture exposed on the surface of the electrode increases, the proportion of the area of ​​the exposed mixture on the electrode surface is preferably 50% or less, more preferably 25% or less, even more preferably 15% or less, and particularly preferably 10% or less, in a plan view.

[0081] In an electrode having a foam metal substrate as a current collector, when at least a portion of the metal substrate is embedded in the surface layer of the mixture layer, from the viewpoint of more reliably integrating the metal substrate and the mixture layer, the thickness of the foam metal substrate is preferably 1% or more, more preferably 2% or more, and particularly preferably 3% or more of the total thickness of the mixture layer (including the thickness of the portion coexisting with the foam metal substrate. Unless otherwise specified, the "thickness of the mixture layer" referred to below means the "total thickness of the mixture layer" herein). Furthermore, from the viewpoint of improving the packing property of the mixture layer in the electrode, the thickness of the foam metal substrate is preferably 30% or less, more preferably 20% or less, and particularly preferably 10% or less of the thickness of the mixture layer.

[0082] In an electrode having a foam metal substrate as a current collector, the thickness of the foam metal substrate (thickness after electrode formation) is preferably 10 μm or more, more preferably 20 μm or more, and particularly preferably 30 μm or more, while it is preferably 300 μm or less, more preferably 200 μm or less, and particularly preferably 100 μm or less.

[0083] The thickness of the foam metal substrate and the thickness of the mixture layer in the electrode are determined by the maximum thickness-wise width of the region where the foam metal substrate can be confirmed and the region where the mixture can be confirmed in an image of a cross section of the electrode in the thickness direction observed with an SEM at a magnification of 50 to 1000. The thickness of the portion of the foam metal substrate embedded in the mixture layer is determined by the maximum thickness-wise width of the portion where the region where the metal substrate can be confirmed and the region where the mixture can be confirmed overlap (the values ​​in the examples described below are determined by these methods).

[0084] The proportion (area ratio) of the mixture exposed on the surface of the electrode can be determined by the ratio (A / B) of the total area of ​​the exposed parts of the mixture (A) to the area of ​​the entire electrode (B) in an image of the electrode surface observed with an SEM at a magnification of 50 to 200 times (the values ​​in the examples described later are determined by this method).

[0085] The electrode can be produced by pressing the mixture to form a molded product (e.g., a pellet) of the mixture and then bonding this to a current collector; by pressing the mixture and current collector together to simultaneously mold the mixture and integrate it with the current collector; or by applying a mixture-containing composition, in which the mixture is dispersed in a solvent, to a current collector, drying the composition, and optionally applying pressure.

[0086] It is preferable to select a solvent for the mixture-containing composition that is less likely to deteriorate the solid electrolyte. In particular, sulfide-based solid electrolytes and hydride-based solid electrolytes undergo chemical reactions with trace amounts of water, so it is preferable to use a nonpolar aprotic solvent, such as hydrocarbon solvents such as hexane, heptane, octane, nonane, decane, decalin, toluene, and xylene. It is particularly preferable to use a super-dehydrated solvent with a water content of 0.001% by mass (10 ppm) or less. Fluorine-based solvents such as "Vertrel (registered trademark)" manufactured by DuPont-Mitsui Fluorochemicals, "Zeorolla (registered trademark)" manufactured by Nippon Zeon Co., Ltd., and "Novec (registered trademark)" manufactured by Sumitomo 3M Co., Ltd., as well as nonaqueous organic solvents such as dichloromethane and diethyl ether can also be used.

[0087] <All-Solid-State Battery> The all-solid-state battery of the present invention has a positive electrode, a negative electrode, and a solid electrolyte layer, and at least one of the positive electrode and the negative electrode is the electrode for the all-solid-state battery of the present invention. Note that the all-solid-state battery of the present invention can be a secondary battery (all-solid-state secondary battery) or a primary battery (all-solid-state primary battery) depending on the selection of the electrode configuration (active material, etc.).

[0088] The positive electrode and the negative electrode are used in the all-solid-state battery in the form of an electrode laminate in which they are laminated with a solid electrolyte layer interposed therebetween, and the electrode laminate is sealed in an exterior body to form the all-solid-state battery.

[0089] A longitudinal cross-sectional view schematically illustrating an example of an all-solid-state battery of the present invention is shown in Fig. 2. The all-solid-state battery 100 shown in Fig. 2 has an electrode laminate 110 having a positive electrode 120, a negative electrode 130, and a solid electrolyte layer 140 interposed therebetween, and this electrode laminate 110 is sealed in a battery container (exterior body) formed by a recessed container 150 and a sealing body 160.

[0090] Fig. 3 is a perspective view schematically illustrating a recessed container 150 constituting the battery container of the all-solid-state battery 100 shown in Fig. 2. As shown in Fig. 3, the recessed container 150 is composed of a bottom surface portion 151 and a side wall portion 152, has an opening portion that opens to the upper side in the figure, and has a recessed cross section.

[0091] The battery 100 shown in FIG. 2 is an example having a positive electrode 120 having a foam metal substrate 122 as a current collector and a negative electrode 130 having a foam metal substrate 132 as a current collector. That is, the positive electrode 120 has a positive electrode mixture layer 121 and a foam metal substrate 122, and the entire foam metal substrate 122, including the end on the positive electrode mixture layer 121 side, is embedded in the surface layer of the positive electrode mixture layer 121. That is, the entire location of the foam metal substrate 122 corresponds to a region where the positive electrode mixture layer and the foam metal substrate coexist. Furthermore, in the positive electrode 120, the end of the foam metal substrate 122 opposite the positive electrode mixture layer 121 side (the lower end in FIG. 2 ) is exposed. The dotted line in the positive electrode 120 indicates the boundary between the region in the positive electrode mixture layer 121 where the foamed metal substrate does not coexist and the region where the positive electrode mixture layer and the foamed metal substrate coexist, and corresponds to the end of the foamed metal substrate 122 on the positive electrode mixture layer 121 side.

[0092] The negative electrode 130 has a negative electrode mixture layer 131 and a foam metal substrate 132, and the entire foam metal substrate 132, including the end on the negative electrode mixture layer 131 side, is embedded in the surface layer of the negative electrode mixture layer 131. That is, the entire location of the foam metal substrate 132 corresponds to the region where the negative electrode mixture layer and the foam metal substrate coexist. Furthermore, in the negative electrode 130, the end of the foam metal substrate 132 on the opposite side to the negative electrode mixture layer 131 side (the upper end in FIG. 2 ) is exposed. Note that the dotted line in the negative electrode 130 indicates the boundary between the region in the negative electrode mixture layer 131 where the foam metal substrate does not coexist and the region where the negative electrode mixture layer and the foam metal substrate coexist, and corresponds to the end of the foam metal substrate 132 on the negative electrode mixture layer 131 side.

[0093] Connection terminals 170, 180 for electrically connecting the all-solid-state battery 100 to a device in which the all-solid-state battery 100 is used are provided on the lower side of the recessed container 150 in the figure. The connection terminal 170 is conductively connected to a conductive path 171 that runs from the inside of the recessed container 150 to the external connection terminal 170. The conductive path 171 is conductively connected to the positive electrode 120 of the electrode stack 110 housed in the recessed container 150, thereby providing electrical continuity between the positive electrode 120 of the electrode stack 110 and the connection terminal 170. In the all-solid-state battery 100 of FIG. 2 , a porous metal substrate 190 similar to that used for a current collector is interposed between the positive electrode 120 of the electrode stack 110 and the conductive path 171 as a conductive connecting member. The action of this porous metal substrate 190 increases the conductivity between the positive electrode 120 and the conductive path 171, and also makes it possible to suppress variations in the internal resistance of individual batteries when a large number of all-solid-state batteries are manufactured (this will be described in detail later).

[0094] Furthermore, the connection terminal portion 180 is conductively connected to a conductive path 181 that runs from the inside of the recessed container 150 to the external connection terminal portion 180, and this conductive path 181 is disposed at the top of the electrode stack 110 in the drawing and is conductively connected to the negative electrode 130 via an elastic conductive member 210 that contacts the negative electrode 130 of the electrode stack 110. This provides electrical continuity between the negative electrode 130 of the electrode stack 110 and the connection terminal portion 180.

[0095] The side wall portion 152 of the recessed container 150 has a support portion 153 that supports the elastic conductive member 210. In the all-solid-state battery 100, as shown in Fig. 3 , the support portion 153 is a protruding portion that is formed at the upper end of the inner circumferential surface of the side wall portion 152 and protrudes in the radial direction, but the support portion for holding the elastic conductive member of the all-solid-state battery may have another shape as long as it can support the elastic conductive member 210.

[0096] 4 is a perspective view schematically illustrating the elastic conductive member 210 included in the all-solid-state battery 100 shown in Fig. 2. The elastic conductive member 210 is made of, for example, a thin metal plate, and has a rectangular shape in plan view as shown in Fig. 4, but can have a shape corresponding to the planar shape of the electrode laminate or the concave container included in the all-solid-state battery.

[0097] The recessed container 150 of the all-solid-state battery 100 shown in Fig. 2 has a plurality of support portions 153 for supporting the elastic conductive member 210 at the upper end of its side wall portion 152. The support portions 153 are formed as protruding portions that protrude in the circumferential direction from the inner circumferential surface of the side wall portion 152. More specifically, the support portions 153 are ceiling walls of a plurality of recesses formed radially outward on the inner circumferential surface of the side wall portion 152. Portions of the conductive paths 181 are exposed on the lower surface and side surface of the ceiling walls. At least the number of support portions 153 formed corresponds to the number of supported portions 211 of the elastic conductive member 210 described below.

[0098] The elastic conductive member 210 has a supported portion 211 and a flat portion 212. A plurality of supported portions 211 are provided at radially outward locations in a plan view of the electrode stack 110 of the all-solid-state battery 101, corresponding to the positions of the supporting portions 153. The supported portions 211 are hook-shaped engaging pieces that engage with the underside of the top wall of the supporting portion 153, and extend from an edge of the elastic conductive member 210 toward the supporting portion 153 (downward in FIG. 2 ). The supported portions 211 have a tip that is folded back toward the supporting portion 153, i.e., the underside of the top wall. The tip of the supported portion 211 contacts the conductive path 181 exposed on the underside and side surfaces of the top wall of the supporting portion 153. As a result, the elastic conductive member 210 functions as a current collector and forms part of the conductive path electrically connecting the negative electrode 130 and the connection terminal 180.

[0099] The elastic conductive member 210 is supported by a support portion 153 formed on the inner circumferential surface of the side wall portion 152 of the recessed container 150, and covers a portion of the opening of the recessed container 150. The area of ​​the elastic conductive member 210 in a plan view is smaller than the area of ​​the opening of the recessed container 150. Note that even if the hook-shaped locking piece of the elastic conductive member 210 is not locked to the underside of the top wall of the support portion 153, as long as the elastic conductive member 210 can be fixed in place with the hook-shaped locking piece pressed into a recess formed on the inner circumferential surface of the side wall portion 152, the elastic conductive member 210 is considered to be locked to the side wall portion 152 of the recessed container 150.

[0100] As shown in Figures 2 and 4, the elastic conductive member 210 has a spring portion 213 that rises from the flat portion 212 toward the negative electrode 130 of the electrode stack 110, and this spring portion 213 contacts the upper surface of the negative electrode 130 of the electrode stack 110 (its porous metal substrate 132) in the figure, pressing the electrode stack 110 toward the inner bottom surface of the recessed container 150.

[0101] In an elastic conductive member having a spring portion, the shape of the spring portion is not particularly limited as long as it can press the electrode stack toward the inner bottom surface of the recessed container. The spring portion 213 of the elastic conductive member 210 shown in FIGS. 2 and 4 is a spring piece inclined from the planar portion 212 toward the negative electrode 130 of the electrode stack 110 (hereinafter, the spring portion 213 may be referred to as the spring piece 213). As shown in FIG. 4, the spring piece 213 is formed by cutting out a portion of the planar portion 212 in a U-shape and is cantilevered on the planar portion 212. In other words, the spring piece 213 in the elastic conductive member 210 shown in FIGS. 2 and 4 is a leaf spring. With this type of elastic conductive member 210, it is only necessary to form the spring piece 213 on a portion of the planar portion 212, which makes it easier to manufacture the elastic conductive member and, ultimately, the all-solid-state battery. Furthermore, by forming the spring pieces 213 by cutting out the flat surface portion 212, the production of the elastic conductive member, and ultimately the production of the all-solid-state battery, can be further facilitated.

[0102] The spring piece 213 has a boundary 213a with the flat portion 212 and a tip portion 213b, and is bent at the boundary 213a and inclined from the boundary 213a to the tip portion 213b toward the electrode stack 110 in order to contact the negative electrode 130 of the electrode stack 110. However, if the tip portion 213b of the spring piece 213 is brought into contact with the negative electrode 130 of the electrode stack 110, there is a risk that the negative electrode 130 may be damaged by the tip portion 213b. Therefore, in the elastic conductive member 210 shown in Figures 2 and 4, the spring piece 213 is bent so that the tip portion 213b faces upward in Figure 2, so that the spring piece 213 contacts the negative electrode 130 at a location other than the tip portion 213b.

[0103] In the elastic conductive member 210 before the all-solid-state battery 100 is assembled, the height from the bottom surface of the flat portion 212 to the point where the spring piece 213 comes into contact with the negative electrode 130 (the height of the spring piece 213) is greater than the height from the bottom surface of the flat portion 212 to the point where the spring piece 213 comes into contact with the negative electrode 130 in the elastic conductive member 210 after the all-solid-state battery 100 is assembled. This allows the spring piece 213 to press against the electrode laminate 110, and a good electrical connection between the elastic conductive member 210 and the negative electrode 130 of the electrode laminate 110 can be maintained.

[0104] Furthermore, by forming the spring portion 213 of the elastic conductive member 210 with a spring piece, it is possible to reduce the thickness of the elastic conductive member 210 excluding the supported portion 211. For example, before assembling the all-solid-state battery 100, the thickness (overall height) of the elastic conductive member 210 excluding the supported portion 211 can be the sum of the thickness of the plate material constituting the planar portion 212 and the height of the spring piece 213. Specifically, the thickness of the plate material: 0.2 mm and the height of the spring piece: 0.5 mm can be combined to make the thickness of the elastic conductive member 210 excluding the supported portion 211 0.7 mm.

[0105] Furthermore, the length (length from the boundary 213a to the tip 213b) of the spring piece 213 can be 3 mm or more, and the width (length in a direction perpendicular to the length direction) can be 1.5 mm or more. An elastic conductive member having spring pieces may have multiple spring pieces. In this case, the shapes of the spring pieces, including their width and length, may vary from one to another to prevent resonance or other reasons. The thickness of the elastic conductive member 210 excluding the supported portion 211 is preferably 1.2 mm or less, more preferably 1 mm or less, and particularly preferably 0.8 mm or less. On the other hand, in order to effectively generate a pressing force on the spring portion 213, the thickness of the elastic conductive member 210 excluding the supported portion 211 is preferably 0.3 mm or more, more preferably 0.4 mm or more, and particularly preferably 0.5 mm or more.

[0106] Furthermore, the position of the edge of the elastic conductive member 210, i.e., the supported portion 211, can be freely set in the height direction (thickness direction of the elastic conductive member 210). Therefore, even if a gap is formed between the sealing body 160 and the elastic conductive member 210, the distance between the sealing body 160 and the point where the spring piece 213 contacts the negative electrode 130 does not increase. As a result, it is possible to prevent the gap between the sealing body 160 and the electrode stack 110 from becoming large, thereby achieving a high capacity of the all-solid-state battery 100. The thickness direction of the elastic conductive member 210 is the vertical direction in FIG. 2 (height direction of the all-solid-state battery 100), and can also be said to be the direction perpendicular to the bottom surface of the flat portion 212.

[0107] The overall thickness of the elastic conductive member 210, including the supported portion 211, can be set appropriately depending on the height of the side wall portion 152 of the recessed container 150 from the bottom surface portion 151. Furthermore, the supported portion 211 only needs to have a height necessary for engagement with the supporting portion 153. The overall thickness of the elastic conductive member 210, including the supported portion 211, can be, for example, 3 mm or less, preferably 2.7 mm or less, and more preferably 2.5 mm or less.

[0108] In the elastic conductive member 210, the spring pieces 213 may be formed by cutting out the flat portion 212 as described above, or may be attached by welding the spring pieces 213 separately to the bottom surface of the flat portion 212. Alternatively, a base for attaching the spring pieces 213 may be provided in advance separately from the flat portion 212, and the spring pieces 213 may be attached to the base to form the entire spring portion. That is, the spring pieces 213 may rise directly from the flat portion 212, or may rise from the flat portion 213 via another element such as a base. Furthermore, the spring pieces 213 may be configured such that both ends of the spring pieces 213 are supported by the flat portion 212 so as to have a convex shape toward the electrode stack 110.

[0109] In installing the elastic conductive member 210 in the all-solid-state battery 100 shown in FIG. 2 , first, the electrode stack 110 is accommodated inside the recessed container 150, and then the elastic conductive member 210 is placed on the upper surface of the electrode stack 110. With the elastic conductive member 210 placed on the upper surface of the electrode stack 110, the tip of the supported portion 211 is positioned between the upper surface of the electrode stack 110 and the supporting portion 153, i.e., the lower surface of the top wall, in the axial direction of the electrode stack 110 (the up-and-down direction in FIG. 2 ). Then, while pressing the supported portion 211 of the elastic conductive member 210 toward the bottom portion 151 of the recessed container 150, the supported portion 211 is supported by the supporting portion 153. More specifically, the tip of the supported portion 211 is engaged with the supporting portion 153, i.e., the lower surface of the top wall. Because the supported portion 211 is pressed downward, the spring piece 213 of the elastic conductive member 210 is pressed in the opposite direction to the negative electrode 130 while in contact with the electrode stack 110. At this time, the spring piece 213 presses the electrode stack 110 toward the bottom portion 151 of the recessed container 150 by its elastic force. This allows the elastic conductive member 210 to make more stable contact with the electrode stack 110, preventing misalignment due to vibration or the like, and maintaining a good electrical connection.

[0110] 2, the recessed container 150 has two support portions 153, 153, but the number of support portions 153 may be three or more. The supported portions 211 of the elastic conductive member 210 may be formed in accordance with the number of support portions 153.

[0111] In addition, an example of a method for fixing the edge (supported portion 211) of the elastic conductive member 210 to the inner surface of the side wall portion 152 of the recessed container 150 is to glue the edge of the elastic conductive member 210 to the inner surface of the side wall portion 152 of the recessed container 150.

[0112] 2, a gap is preferably formed between the elastic conductive member 210 and the sealing member 160. In other words, it is preferable that the elastic conductive member 210 and the sealing member 160 are not in contact with each other. This makes it possible to avoid contact between the elastic conductive member 210 and the sealing member 160 even if the elastic conductive member 210 is pushed toward the sealing member 160 due to a change in volume of the electrode stack 110.

[0113] In the all-solid-state battery 100 shown in FIG. 2 , the electrode laminate 110 is arranged so that the positive electrode 120 is located on the inner bottom surface side of the recessed container 150 and the negative electrode 130 is located on the sealing body 160 side (elastic conductive member 210 side); however, an all-solid-state battery can also be configured by arranging the electrode laminate so that the negative electrode is located on the inner bottom surface side of the recessed container and the positive electrode is located on the sealing body side (elastic conductive member side).

[0114] (Electrode) In the all-solid-state battery of the present invention, only one of the positive electrode and the negative electrode may be the electrode of the present invention, or both the positive electrode and the negative electrode may be the electrode of the present invention.

[0115] When an all-solid-state battery has the electrode of the present invention only as the positive electrode, the negative electrode may be one having the same configuration as the electrode of the present invention except for the composition of the current collector; one having the same configuration as the electrode of the present invention except for not containing a sulfide-based solid electrolyte and containing a solid electrolyte different from the sulfide-based solid electrolyte; one using metallic lithium or lithium-aluminum alloy foil as is; one having metallic lithium or lithium-aluminum alloy foil and a current collector; or the like.

[0116] When an all-solid-state battery has the electrode of the present invention only as the negative electrode, the positive electrode can be, for example, a positive electrode having the same configuration as the electrode of the present invention except for the composition of the current collector; a positive electrode having the same configuration as the electrode of the present invention except for not containing a sulfide-based solid electrolyte and containing a solid electrolyte different from the sulfide-based solid electrolyte;

[0117] Between the positive electrode and the negative electrode of an all-solid-state secondary battery, corrosion of the current collector is more likely to occur in the positive electrode. Therefore, from the viewpoint of better ensuring the effect of suppressing an increase in the internal resistance of the battery, in the all-solid-state secondary battery of the present invention, it is preferable that at least the positive electrode is the electrode of the present invention, and it is more preferable that both the positive electrode and the negative electrode are the electrodes of the present invention.

[0118] (Solid Electrolyte Layer) Specific examples of the solid electrolyte constituting the solid electrolyte layer of the all-solid-state battery include the same solid electrolytes as those exemplified above as those that can be contained in the positive electrode mixture. Among the solid electrolytes exemplified above, it is preferable to use a sulfide-based solid electrolyte because it has high lithium ion conductivity and also has the function of improving formability, it is more preferable to use a sulfide-based solid electrolyte having an argyrodite-type crystal structure, and it is even more preferable to use one represented by the general composition formula (1), the general composition formula (2), or the general composition formula (3).

[0119] The solid electrolyte layer can be formed by a method of compressing a solid electrolyte by pressure molding or the like; a method of applying a solid electrolyte layer-forming composition prepared by dispersing a solid electrolyte in a solvent onto a substrate, a positive electrode, or a negative electrode, drying the composition, and, if necessary, performing pressure molding such as pressing.

[0120] The solid electrolyte layer may contain a binder such as an acrylic resin or a fluororesin to maintain its shape.

[0121] The solid electrolyte layer may also have a porous support such as a resin nonwoven fabric, in which case a solid electrolyte sheet having the support is obtained.

[0122] It is desirable to select a solvent for use in the solid electrolyte layer-forming composition that is less likely to deteriorate the solid electrolyte, similar to the solvent used in the mixture-containing composition. It is preferable to use the various solvents exemplified above as solvents for the mixture-containing composition, and it is particularly preferable to use an ultra-dehydrated solvent with a water content of 0.001 mass % (10 ppm) or less.

[0123] The thickness of the solid electrolyte layer is preferably 10 to 200 μm.

[0124] (Method for manufacturing electrode laminate) There are no particular limitations on the method for manufacturing an electrode laminate used when constructing an all-solid-state battery using an electrode laminate having a positive electrode, a negative electrode, and a solid electrolyte layer interposed therebetween. For example, the electrode laminate can be manufactured by a manufacturing method including the following first to third steps.

[0125] In the first step, the mixture (positive electrode mixture or negative electrode mixture) is placed in a mold and pressure-molded. The pressure applied during pressure molding in the first step is preferably, for example, 30 to 500 MPa.

[0126] In the next step, a porous metal substrate is placed on the mixture formed by pressure molding in step 1, and then, in step 3, the mixture and the porous metal substrate are pressed together. By applying pressure in step 3, the porous metal substrate is embedded in the mixture from the end on the mixture side, and the mixture is further compressed, and the porous metal substrate is compressed in the thickness direction, thereby integrating the mixture layer (positive electrode mixture layer or negative electrode mixture layer) and the porous metal substrate to form an electrode (positive electrode or negative electrode).

[0127] As described above, in this third step, the porous metal substrate is compressed in the thickness direction, and the degree of compression is, from the viewpoint of ensuring a more reliable bond between the porous metal substrate and the mixture layer, preferably the thickness of the porous metal substrate after compression is 30% or less of the thickness before compression, more preferably 20% or less, and particularly preferably 10% or less. Furthermore, from the viewpoint of retaining a certain amount of mixture in the pores of the porous metal substrate and increasing the bonding strength between the porous metal substrate and the mixture layer, the thickness of the porous metal substrate after compression in the third step is preferably 1% or more of the thickness before compression, more preferably 2% or more.

[0128] The surface pressure during the pressurization in the third step is preferably 800 MPa or more, more preferably 1000 MPa or more, and particularly preferably 1200 MPa or more, for example, in order to compress and mold the mixture and sufficiently increase the density of the mixture layer. Although the upper limit of the surface pressure during the pressurization in the third step is not particularly specified, in a general pressurization device, the upper limit is usually about 2000 MPa.

[0129] By going through the first to third steps, an electrode (positive or negative electrode) can be obtained in which at least a portion of the porous metal substrate, including the end portion on the mixture layer side (a certain range in the thickness direction from the end portion of the porous metal substrate), is embedded in the surface layer portion of the mixture layer and is integrated with the mixture layer, and the other end portion of the porous metal substrate is exposed on the surface of the electrode.

[0130] If the surface pressure during the application of pressure in the third step becomes too high, cracks may occur when the porous metal substrate is compressed. However, even if the substrate is broken into pieces, the ends of the pieces can contribute to reducing the contact resistance if they are exposed on the surface of the electrode.

[0131] The positive electrode and the negative electrode are prepared through the first, second and third steps, and are then arranged on both sides of the solid electrolyte layer, and if necessary, pressed to form an electrode stack.

[0132] Furthermore, before the first step, a preliminary step of putting the solid electrolyte into a mold and pressure-molding it may be provided, and a mixture (a positive electrode mixture or a negative electrode mixture) may be placed on the solid electrolyte pressure-molded in this preliminary step. Thereafter, the first step, the second step, and the third step may be carried out in sequence to produce an integrated product of the solid electrolyte layer and the electrode (a positive electrode or a negative electrode), which may be used in an electrode laminate.

[0133] The surface pressure during pressure molding in the preliminary step is preferably set to, for example, 30 to 120 MPa.

[0134] Alternatively, an electrode stack can be produced by forming one of a positive electrode and a negative electrode on one side of a solid electrolyte layer through the preliminary step, the first step, the second step, and the third step, and then sequentially performing the first step, the second step, and the third step on the other side of the solid electrolyte layer to form the other electrode (negative electrode or positive electrode).

[0135] (Exterior Body) For the exterior body of the all-solid-state battery, there can be used a battery container having a concave container (exterior container) and a sealing body (lid) as shown in FIG. 2; a flat (coin-shaped, button-shaped, etc.) or tubular (cylindrical, rectangular, etc.) battery container having a metal exterior can and a metal sealing body; a battery container made of a laminate film exterior body made of a metal laminate film such as an aluminum laminate film; and the like.

[0136] 2, the battery container having a recessed container and a sealing body can be made of ceramics or resin, and the sealing body can be made of ceramics, resin, or metal (such as an iron-nickel alloy or an iron-based alloy such as an iron-nickel-cobalt alloy).

[0137] In the concave container, the connection terminal portion and the conductive path connecting the electrode of the electrode stack and the connection terminal portion can be made of a metal such as manganese, cobalt, nickel, copper, molybdenum, silver, palladium, tungsten, platinum, or gold, or an alloy containing these metals.

[0138] The recessed container and the sealing body can be sealed by bonding them together with an adhesive. In addition, when a metal sealing body is used, as shown in FIG. 2 , a seal ring 200 made of metal (such as an iron-nickel alloy or an iron-based alloy such as an iron-nickel-cobalt alloy) can be placed on the sealing body 160 side (upper side in the figure) of the side wall 152 of the recessed container 150, so that the sealing body side of the side wall is made of metal, and the recessed container and the sealing body can be welded together to seal the container.

[0139] The shape of the exterior body in a plan view may be circular or polygonal such as quadrilateral (square or rectangle). In the case of a polygonal shape, the corners may be curved.

[0140] (Elastic conductive member) The elastic conductive member is not particularly limited as long as it functions as a leaf spring that presses the electrode stack toward the inner bottom surface of the recessed container. Specifically, examples include an elastic conductive member having a supported portion 211 shaped according to the support portion 153 of the recessed container 150 and a flat portion 212 with a spring portion (spring piece) 213, as shown in Figures 2 and 4; an elastic conductive member having a cross-sectional shape that has a locking portion shaped according to the support portion of the recessed container and a recess that presses the electrode stack; etc.

[0141] The elastic conductive member can be formed from a plate made of nickel, iron, copper, chromium, cobalt, titanium, aluminum, or an alloy thereof. Of the metals exemplified above, stainless steel plate and nickel-plated stainless steel plate are preferred as the metal constituting the elastic conductive member, and in order to facilitate the function of the leaf spring, stainless steel for springs such as SUS301-CSP, SUS304-CSP, SUS316-CSP, SUS420J2-CSP, SUS631-CSP, and SUS632J1-CSP are more preferred.

[0142] The thickness of the metal plate constituting the elastic conductive member is preferably 0.05 mm or more, more preferably 0.07 mm or more, and even more preferably 0.1 mm or more, in order to ensure a certain level of pressing force against the electrode laminate. On the other hand, in order to prevent the elastic conductive member from becoming too thick, which would increase the storage volume inside the battery container, and to make the elastic conductive member easily deformable so that it can be easily engaged with the side wall portion of the concave container, the thickness of the metal plate constituting the elastic conductive member is preferably 0.5 mm or less, more preferably 0.4 mm or less, and even more preferably 0.3 mm or less.

[0143] (Conductive Connecting Member) As in the all-solid-state battery shown in Fig. 2, a conductive connecting member is preferably disposed between the electrode laminate and the inner bottom surface of the recessed container associated with the battery container to prevent gaps from occurring due to variations in the thickness (height) of individual components, thereby establishing electrical continuity between the conductive connecting member and the conductive path of the recessed container. That is, when the conductive connecting member is disposed, the electrode on the inner bottom surface side of the recessed container in the electrode laminate (positive electrode 110 in the case of the all-solid-state battery 100 shown in Fig. 2) and the conductive path of the recessed container (conductive path 171 in the case of the all-solid-state battery 100 shown in Fig. 2) are electrically connected via the conductive connecting member (porous metal substrate 190 in the case of the all-solid-state battery shown in Fig. 2).

[0144] An example of a conductive connecting member is the porous metal substrate that constitutes the current collector of the electrode described above. In particular, a foamed metal substrate easily undergoes plastic deformation when a force is applied in the thickness direction. Therefore, when pressed by the electrode laminate during the formation of an all-solid-state battery, the foamed metal substrate easily undergoes compressive deformation and reduces its thickness in accordance with the degree of variation (deviation from the design value) in the thickness (height) of each component. This improves contact between the porous metal layer of the electrode laminate and the current collector, and also makes it possible to homogenize the degree of conduction between the porous metal layer and the electrode laminate in each all-solid-state battery when a large number of all-solid-state batteries are manufactured. When a porous metal substrate, particularly a foamed metal substrate, is used in an all-solid-state battery, these effects enable a lower internal resistance and a reduction in the variation in individual internal resistances.

[0145] As the foamed metal substrate, it is preferable to use "Celmet (registered trademark)" manufactured by Sumitomo Electric Industries, Ltd., as in the case of the electrode current collector.

[0146] The thickness of the foamed metal substrate in the all-solid-state battery after assembly is preferably 20 μm or more, more preferably 100 μm or more, from the viewpoint of ensuring its function more satisfactorily. There is no particular upper limit to the thickness of the foamed metal substrate in the all-solid-state battery, but from the viewpoint of suppressing the volume of components not involved in power generation inside the battery container, the thickness is preferably 500 μm or less, more preferably 300 μm or less.

[0147] The thickness of the conductive connecting member is determined by the maximum width in the thickness direction in an image of a cross section of the conductive connecting member observed with an SEM at a magnification of 50 to 1000 times (the values ​​in the examples described below are determined by these methods).

[0148] As described above, the conductive connecting member is preferably a porous metal substrate compressed in the thickness direction, and the thickness thereof is preferably 90% or less, and more preferably 80% or less, of the thickness (thickness before compression) of the porous metal substrate used to form the conductive connecting member. Therefore, the thickness of the porous metal substrate used to form the conductive connecting member is preferably 150 to 3000 μm.

[0149] Furthermore, the porosity (porosity before compression) of the porous metal substrate used to form the conductive connecting member is preferably 99.5% or less, more preferably 99% or less, and even more preferably 98.5% or less, from the viewpoint of making it easier to perform plastic deformation by pressing the electrode laminate and better ensuring the effect of reducing the internal resistance of the all-solid-state battery and the effect of suppressing variation therein; and from the viewpoint of ensuring sufficient strength for use, it is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more.

[0150] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0151] (Example 1) Lithium titanate (Li) having an average particle size of 2 μm ４ Ti ５ O １２ , negative electrode active material) and a sulfide-based solid electrolyte (Li ６ P.S. ５ Cl) and graphene (conductive additive) were mixed in a mass ratio of 50:41:9 to prepare a negative electrode mixture.

[0152] In addition, LiNbO ３ LiCoO having an average particle size of 5 μm on which a coating layer of ２ (positive electrode active material) and a sulfide-based solid electrolyte (Li ６ P.S. ５ Cl) and graphene were mixed in a mass ratio of 65:30.7:4.3 to prepare a positive electrode mixture.

[0153] Next, a sulfide-based solid electrolyte (Li ６ P.S. ５ A powder of HCl) was placed in a powder molding die and subjected to pressure molding at a surface pressure of 70 MPa using a press to form a provisionally molded layer of a solid electrolyte layer. Furthermore, the negative electrode mixture was placed on the upper surface of the provisionally molded layer of the solid electrolyte layer and pressure molding was performed at a surface pressure of 50 MPa to form a provisionally molded layer of a negative electrode on the provisionally molded layer of the solid electrolyte layer.

[0154] Next, a foamed metal substrate (Celmet (registered trademark) made by Sumitomo Electric Industries, Ltd., made of a Ni-Cr alloy with Ni and Cr contents of 95% by mass and 5% by mass, respectively) cut to a diameter of 7.25 mm (thickness: 1.1 mm, porosity: 98%, basis weight: 347 g / m) was applied onto the provisionally formed layer of the negative electrode formed on the provisionally formed layer of the solid electrolyte layer. ２ ) was placed on the negative electrode, and pressure molding was performed at a surface pressure of 300 MPa to form an integrated body of the solid electrolyte layer and the negative electrode.

[0155] Furthermore, after the mold was turned upside down, the positive electrode mixture was placed on the upper surface of the solid electrolyte layer in the mold (the surface opposite to the surface having the negative electrode), and pressure molding was performed at a surface pressure of 50 MPa, thereby forming a provisionally molded layer of the positive electrode on the solid electrolyte layer.

[0156] Next, a cut foamed metal substrate made of a Ni—Cr alloy having the same composition as that used for the negative electrode was placed on the provisionally molded layer of the positive electrode formed on the solid electrolyte layer, and pressure molding was performed at a surface pressure of 1400 MPa to obtain an electrode laminate.

[0157] In the obtained electrode laminate, the thickness of the negative electrode mixture layer of the negative electrode, the thickness of the porous metal substrate, and the thickness of the portion of the porous metal substrate embedded in the negative electrode mixture layer were 1400 μm, 60 μm (5% of the thickness of the porous metal substrate before use in the negative electrode), and 60 μm (100% of the total thickness of the porous metal substrate), respectively. In addition, the area ratio of the portion of the negative electrode mixture exposed on the surface of the negative electrode was 7%.

[0158] In addition, in the obtained electrode laminate, the thickness of the positive electrode mixture layer of the positive electrode, the thickness of the porous metal substrate, and the thickness of the portion of the porous metal substrate embedded in the positive electrode mixture layer were 800 μm, 60 μm (5% of the thickness of the porous metal substrate before use in the positive electrode), and 60 μm (100% of the total thickness of the porous metal substrate), respectively. In addition, the area ratio of the portion of the positive electrode mixture exposed on the surface of the positive electrode was 7%.

[0159] A ceramic-made recessed container (2.5 mm deep) with a structure similar to that shown in FIGS. 2 and 3 was constructed. The upper sidewall of the container was fitted with a seal ring made of an iron-nickel-cobalt alloy. A Ni foam metal substrate cut to a diameter of 7.25 mm was placed on the inner bottom of the container, contacting the conductive path of the positive electrode. The electrode stack was then placed on top of the metal substrate, with the positive electrode facing downward. Furthermore, an elastic conductive member made of a stainless steel plate (0.3 mm thick) with a shape similar to that shown in FIGS. 2 and 4 was placed on top of the negative electrode of the electrode stack. The supported portion of the elastic conductive member was then engaged with the support portion of the recessed container. The spring piece of the elastic conductive member was then bent toward the negative electrode of the electrode stack, with its tip pointing toward the flat portion. The spring piece was then brought into contact with the negative electrode of the electrode stack at a point closer to the boundary with the flat portion than the tip, pressing the electrode stack toward the inner bottom of the recessed container. Thereafter, a sealing member made of an iron-nickel-cobalt alloy plate (thickness 0.1 mm) was placed on the seal ring of the recessed container, and the sealing member and the recessed container (seal ring) were welded to seal the battery container, thereby obtaining an all-solid-state secondary battery. In the obtained all-solid-state secondary battery, as described above, the elastic conductive member pressed the electrode stack against the inner bottom surface of the recessed container, thereby causing the electrode stack to press against the conductive connecting member made of a foamed metal substrate. Furthermore, the thickness of the conductive connecting member in the all-solid-state secondary battery was 200 μm.

[0160] (Example 2) The foamed metal substrates serving as current collectors for the positive and negative electrodes were made of a substrate (basis weight: 388 g / m) made of a Ni-Cr alloy containing 85% by mass of Ni and 15% by mass of Cr. ２ An all-solid-state secondary battery was fabricated in the same manner as in Example 1, except that the above-mentioned material was changed to the above-mentioned material.

[0161] (Example 3) The foamed metal substrates serving as current collectors for the positive and negative electrodes were replaced with substrates (basis weight: 440 g / m) made of a Ni—Cr alloy containing 75% by mass of Ni and 25% by mass of Cr. ２ An all-solid-state secondary battery was fabricated in the same manner as in Example 1, except that the above-mentioned material was changed to the above-mentioned material.

[0162] (Example 4) The foamed metal substrates serving as current collectors for the positive and negative electrodes were replaced with substrates (basis weight: 508 g / m) made of a Ni-Cr alloy containing 65% by mass of Ni and 35% by mass of Cr. ２ An all-solid-state secondary battery was fabricated in the same manner as in Example 1, except that the above-mentioned material was changed to the above-mentioned material.

[0163] (Comparative Example 1) The foamed metal substrates serving as current collectors for the positive and negative electrodes were replaced with a substrate made of pure Ni containing no Cr (basis weight: 330 g / m ２ An all-solid-state secondary battery was fabricated in the same manner as in Example 1, except that the above-mentioned material was changed to the above-mentioned material.

[0164] (Comparative Example 2) The foamed metal substrates serving as the current collectors of the positive and negative electrodes were replaced with substrates (basis weight: 388 g / m) made of a Ni—Sn alloy containing 85% by mass of Ni and 15% by mass of Sn, respectively. ２ An all-solid-state secondary battery was fabricated in the same manner as in Example 1, except that the above-mentioned material was changed to the above-mentioned material.

[0165] The all-solid-state secondary batteries of the Examples and Comparative Examples were charged at a constant current of 4 mA until the voltage reached 2.6 V, then charged at a constant voltage of 2.6 V until the current reached 0.05 mA, and then discharged at a constant current of 0.4 mA until the voltage reached 1.0 V. Thereafter, the internal resistance of each battery was measured at 1 kHz with an applied voltage of 10 mV to determine the initial resistance.

[0166] Furthermore, each battery whose initial resistance value was measured was stored in a thermostatic chamber at 115°C for 7 days, taken out, and cooled to room temperature. Then, constant current charging, constant voltage charging, constant current discharging, and internal resistance measurement were carried out under the same conditions as when the initial resistance value was measured, and the resistance after storage was determined.

[0167] Then, for each battery, the difference between the post-storage resistance and the initial resistance was divided by the initial resistance, and the value was expressed as a percentage to determine the resistance increase rate.

[0168] Furthermore, the battery whose resistance had been measured after storage was disassembled, and the presence or absence of corrosion of the positive and negative electrode current collectors was confirmed by SEM.

[0169] The results are shown in Table 1.

[0170]

[0171] As shown in Table 1, the all-solid-state secondary batteries of Examples 1 to 4, in which the positive and negative electrode current collectors were made of a Ni—Cr alloy of a suitable composition, had a lower rate of increase in resistance due to high-temperature storage, and the increase in resistance was suppressed, compared to the battery of Comparative Example 1, which used a Ni current collector, and the battery of Comparative Example 2, which was made of a Ni—Sn alloy containing no Cr.

[0172] Furthermore, the all-solid-state secondary batteries of Examples 1 to 3, in which the Cr content in the Ni—Cr alloy was 30 mass % or less, were able to lower the resistance of the current collector compared to Example 4, in which the Cr content was high, and thus were able to lower the initial resistance of the battery.

[0173] When the batteries of the Examples and Comparative Examples were disassembled after measuring the resistance after storage and the electrodes (positive and negative electrodes) were examined, a bulk layer-like product that was thought to be NiS (nickel sulfide) was observed in the batteries of Comparative Examples 1 and 2, whereas this production was suppressed in the batteries of Examples 1 and 2, and corrosion of the current collector due to reaction with the sulfide-based solid electrolyte contained in the electrodes and gas derived therefrom was successfully suppressed.

[0174] The present invention can be implemented in other forms without departing from the spirit of the present invention. The embodiments disclosed in this application are merely examples, and the present invention is not limited to these embodiments. The scope of the present invention shall be interpreted in accordance with the appended claims rather than the description in the above specification, and all modifications within the scope of the claims are included in the scope of the claims.

[0175] The all-solid-state battery of the present invention can be used in the same applications as conventionally known primary batteries and secondary batteries, but since it has a solid electrolyte instead of an organic electrolyte solution, it has excellent heat resistance and can be preferably used in applications where it is exposed to high temperatures. The electrode for an all-solid-state battery of the present invention can constitute the all-solid-state battery of the present invention.

[0176] REFERENCE SIGNS LIST 100 All-solid-state battery 110 Electrode laminate 120 Positive electrode 121 Positive electrode mixture layer 122 Positive electrode current collector 130 Negative electrode 131 Negative electrode mixture layer 132 Negative electrode current collector 140 Solid electrolyte layer 150 Concave container 151 Bottom surface 152 Side wall 153 Support portion 160 Sealing body 170 Connection terminal portion 171 Conductive path 180 Connection terminal portion 181 Conductive path 190 Porous metal substrate (conductive connecting member) 200 Seal ring 210 Elastic conductive member 211 Supported portion 212 Planar portion 213 Spring portion (spring piece) 213a Boundary 213b Tip portion

Claims

1. An electrode for an all-solid-state battery having a mixture containing an active material and a sulfide-based solid electrolyte, and a current collector, wherein the current collector is composed of an alloy containing Ni and Cr, the Ni content of the alloy is 60 mass% or more, and the Cr content of the alloy is 0.1 mass% or more and 40 mass% or less.

2. The electrode for an all-solid-state battery according to claim 1, wherein the Ni content in the alloy is 70 mass % or more.

3. The electrode for an all-solid-state battery according to claim 1, wherein the Cr content in the alloy is 30 mass % or less.

4. The electrode for an all-solid-state battery according to claim 1, wherein the sulfide-based solid electrolyte contains an argyrodite-type solid electrolyte.

5. The electrode for an all-solid-state battery according to claim 1, wherein the current collector is made of a porous metal substrate, and at least a portion of the mixture is filled in the pores of the porous metal substrate.

6. The electrode for an all-solid-state battery according to claim 5, wherein one end of the porous metal substrate is exposed on the surface.

7. The weight of the porous metal substrate is 600 g / m ２ The electrode for an all-solid-state battery according to claim 5, wherein:

8. An all-solid-state battery comprising a positive electrode, a negative electrode, and a solid electrolyte layer, wherein at least one of the positive electrode and the negative electrode is an electrode for an all-solid-state battery according to any one of claims 1 to 7.

9. The all-solid-state battery according to claim 8, wherein at least the positive electrode is the all-solid-state battery electrode according to any one of claims 1 to 7.

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