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

Abstract

In all-solid-state batteries using electrodes comprising sulfide-based solid electrolytes, corrosion of the current collector is suppressed to prevent an increase in electrode resistance. The electrode for an all-solid-state battery of the present invention is characterized by having a mixture comprising an active material and a sulfide-based solid electrolyte, and a current collector composed of an alloy comprising Ni and Cr, wherein the Ni content in the alloy is 60% by mass or more, and the Cr content in the alloy is 0.1% by mass or more and 40% by mass or less. The all-solid-state battery of the present invention is characterized by having a positive electrode, a negative electrode, and a solid electrolyte layer, wherein at least one of the positive electrode and the negative electrode is the electrode for an all-solid-state battery of the present invention.

Description

Technical Field

[0001] The present invention relates to electrodes for all-solid-state batteries that can be used in the assembly of all-solid-state batteries and to all-solid-state batteries using the same. Background Technology

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

[0003] Currently, in lithium batteries that can meet this requirement, especially lithium-ion batteries, lithium-containing composite oxides such as lithium cobalt oxide (LiCoO2) and lithium nickel oxide (LiNiO2) are used as positive electrode active materials, graphite is used as negative electrode active materials, and organic electrolytes containing organic solvents and lithium salts are used as non-aqueous electrolytes.

[0004] Moreover, with the further development of lithium-ion battery application equipment, while demanding longer lifespan, higher capacity, and higher energy density of lithium-ion batteries, there is also a requirement for the reliability of lithium-ion secondary batteries with longer lifespan, higher capacity, and higher energy density.

[0005] However, the organic electrolytes used in lithium-ion batteries contain organic solvents, which are flammable substances. Therefore, in the event of a short circuit or other abnormal situation, the organic electrolyte may generate abnormal heat. Furthermore, with the increasing energy density of lithium-ion batteries and the growing trend of increasing organic solvent content in organic electrolytes in recent years, the reliability of lithium-ion batteries is becoming increasingly critical.

[0006] Under the aforementioned circumstances, all-solid-state lithium batteries (all-solid-state batteries) that do not use organic solvents were also discussed. All-solid-state lithium batteries use sheets and molded bodies of solid electrolytes that do not use organic solvents to replace the conventional organic solvent-based electrolytes. This eliminates concerns about abnormal heat generation associated with solid electrolytes and provides high reliability.

[0007] As solid electrolytes, sulfide-based solid electrolytes, hydride-based solid electrolytes, halide-based solid electrolytes, and oxide-based solid electrolytes were explored. Among them, due to the high conductivity of lithium ions, the development of sulfide-based solid electrolytes is progressing rapidly. Furthermore, an all-solid-state battery that uses sulfide-based solid electrolytes for the positive electrode, negative electrode, and solid electrolyte layer has been proposed (Patent Document 1).

[0008] However, it was determined that due to the high reactivity of sulfide-based solid electrolytes, when used as electrodes, repeated charging and discharging can cause the current collector to react with the solid electrolyte, resulting in increased resistance at the interface.

[0009] In contrast, Patent Document 2 discloses a current collector for an all-solid-state battery in which a coating layer comprising powdered carbon material, acid-modified polyvinylidene fluoride, and polyN-vinylpyrrolidone is formed on the surface of a sheet-like conductive substrate, and proposes to improve the corrosion resistance of the current collector by utilizing the above-mentioned coating layer.

[0010] In addition, in Patent Documents 3 and 4, porous metal bodies made of Ni and Cr alloys and porous metal bodies made of Ni, Cr and Sn alloys were proposed as metal porous bodies that can be used as current collectors in lithium-ion secondary batteries, capacitors, fuel cells, various filters, catalyst supports and other applications.

[0011] Existing technical documents

[0012] Patent documents

[0013] Patent Document 1: Japanese Patent Application Publication No. 2023-022836

[0014] Patent Document 2: Japanese Patent Application Publication No. 2020-198275

[0015] Patent Document 3: Japanese Patent Application Publication No. 2012-149282

[0016] Patent Document 4: Japanese Patent Application Publication No. 2014-065955 Summary of the Invention

[0017] The problem that the invention aims to solve

[0018] The purpose of this invention is to suppress corrosion of the current collector and prevent the electrode resistance from increasing in an all-solid-state battery that uses electrodes containing sulfide-based solid electrolytes.

[0019] Methods for solving problems

[0020] The electrode for an all-solid-state battery of the present invention is characterized in that it comprises an active material and a sulfide-based solid electrolyte, and a current collector, wherein the current collector is composed of an alloy comprising Ni and Cr, wherein the content of Ni in the alloy is 60% by mass or more, and the content of Cr in the alloy is 0.1% by mass or more and 40% by mass or less.

[0021] Furthermore, the all-solid-state battery of the present invention is characterized by having 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 the all-solid-state battery of the present invention.

[0022] Invention Effects

[0023] According to the present invention, an electrode for an all-solid-state battery is provided, which includes a sulfide-based solid electrolyte and suppresses corrosion of the current collector, thereby suppressing the increase in resistance; an all-solid-state battery having the above-described electrode is also provided, which suppresses the increase in internal resistance. Attached Figure Description

[0024] Figure 1 These are scanning electron microscope images used to illustrate the surface state of the electrodes for all-solid-state batteries of the present invention.

[0025] Figure 2 This is a cross-sectional view schematically illustrating an example of the all-solid-state battery of the present invention.

[0026] Figure 3 yes Figure 2 A three-dimensional view of the concave container of an all-solid-state battery.

[0027] Figure 4 yes Figure 2 A three-dimensional view of the elastic conductive component of an all-solid-state battery. Detailed Implementation

[0028] <Electrodes for all-solid-state batteries>

[0029] The electrode for an all-solid-state battery of the present invention (hereinafter, sometimes simply referred to as "electrode") comprises an active material and a sulfide-based solid electrolyte, and a current collector. Furthermore, the current collector is composed of an alloy containing Ni (nickel) and Cr (chromium) (hereinafter, sometimes referred to as "Ni-Cr alloy"), wherein the Ni content in the alloy is 60% by mass or more, and the Cr content in the alloy is 0.1% by mass or more and 40% by mass or less.

[0030] Because of Ni's high conductivity, using a current collector made of Ni can reduce electrode resistance and effectively collect electricity generated by the electrolyte. However, if the electrolyte in the electrode contains a sulfide-based solid electrolyte, the current collector will corrode due to contact with the sulfide-based solid electrolyte, or the current collector will corrode due to the generation of sulfide gases such as hydrogen sulfide within the battery containing the electrode.

[0031] Therefore, in the electrode of the present invention, a current collector made of an alloy containing Ni and Cr is used. In the above-mentioned current collector, corrosion caused by contact with sulfide-based solid electrolyte and contact with gases from sulfide-based solid electrolyte can be suppressed by the action of Cr.

[0032] However, in current collectors made of alloys containing Ni and Cr, Cr also has the effect of reducing the conductivity of the current collector and increasing the resistance of the electrodes.

[0033] Therefore, in the electrode of the present invention, by setting the content of Ni and the content of Cr in the alloy of Ni and Cr constituting the current collector to specific ranges, it is possible to achieve good conductivity and suppress corrosion of sulfide-based solid electrolytes, reduce the initial resistance, and suppress the increase in resistance caused by corrosion.

[0034] Therefore, in the all-solid-state battery using the electrode of the present invention (the all-solid-state battery of the present invention), the internal resistance can be reduced and the increase of internal resistance during use or storage can be well suppressed.

[0035] The electrode of the present invention can be used as at least one of the positive and negative electrodes of a secondary battery (all-solid-state secondary battery), and can also be used as at least one of the positive and negative electrodes of a primary battery (all-solid-state primary battery).

[0036] The electrode comprises an active material and a sulfide-based solid electrolyte, and a current collector, for example, having a structure in which a layer (i.e., an agent layer) formed of the aforementioned agent is present on one or both sides of the current collector. Alternatively, if the current collector is porous, the electrode may be integrally formed by incorporating at least a portion of the agent layer into the pores of the current collector.

[0037] In the case where the electrode is the positive electrode of an all-solid-state battery, the mixture (positive electrode mixture) contains the positive electrode active material and the sulfide-based solid electrolyte.

[0038] When the electrode is the positive electrode of an all-solid-state primary battery, the positive electrode active material can be the same material used in conventionally known non-aqueous electrolyte primary batteries, etc. Specifically, examples include manganese dioxide, lithium-containing manganese oxides (e.g., LiMn3O6, structures having the same crystal structure as manganese dioxide (β-type, γ-type, or a mixture of β-type and γ-type, etc.), with 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, and especially preferably composite oxides), Li... a Ti 5 / 3 Lithium-containing composite oxides such as O4 (4 / 3≤a<7 / 3), vanadium oxides, niobium oxides, titanium oxides, sulfides such as iron disulfide, fluorinated graphite, silver sulfides such as Ag2S, and nickel oxides such as NiO2.

[0039] When the electrode is the positive electrode of an all-solid-state secondary battery, the positive electrode active material can be the same material used in previously known non-aqueous electrolyte secondary batteries, etc. Specifically, an example can be made from Li... 1-x M r Mn 2-rO4 (where 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; 0 ≤ x ≤ 1, 0 ≤ r ≤ 1), the spinel-type lithium manganese composite oxide, composed of Li r Mn (1-s-t) Ni s M t O (2-u) F v (where 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; 0 ≤ r ≤ 1.2, 0 < s < 0.5, 0 ≤ t ≤ 0.5, u + v < 1, -0.1 ≤ u ≤ 0.2, 0 ≤ v ≤ 0.1), the layered compound, composed of Li 1-x Co 1-r M r O2 (where 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; 0 ≤ x ≤ 1, 0 ≤ r ≤ 0.5), the lithium cobalt composite oxide, composed of Li<了 1-x Ni 1-r M r O2 (where 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; 0 ≤ x ≤ 1, 0 ≤ r ≤ 0.5), the lithium nickel composite oxide, composed of Li 1+s-x M 1-r N r PO4F s (where 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; 0 ≤ x ≤ 1, 0 ≤ r ≤ 0.5, 0 ≤ s ≤ 1), the olivine-type composite oxide, composed of Li 2-x M 1-r N r P2O7 (where 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; 0 ≤ x ≤ 2, 0 ≤ r ≤ 0.5), the pyrophosphate compound, etc. They can be used alone, or two or more of them can be used in combination.

[0040] When the electrode is the 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. It should be noted that the positive electrode active material can be primary particles or secondary particles formed by the aggregation of primary particles. Using a positive electrode active material with an average particle size within the above-mentioned range increases the number of interfaces with the solid electrolyte contained in the positive electrode, thereby further improving the battery's output characteristics.

[0041] The average particle size of various particles (positive electrode active materials, solid electrolytes, etc.) mentioned in this specification refers to the value of the diameter at 50% of the cumulative fraction of the volume reference when calculating the integral volume starting from the smallest particle using a particle size distribution measuring device (such as the Microtrac particle size distribution measuring device "HRA9320" manufactured by Nikkiso Co., Ltd.). 50 ).

[0042] In the case where the electrode is the positive electrode of an all-solid-state secondary battery, the positive electrode active material preferably has a reaction inhibition layer on its surface for inhibiting the reaction with the solid electrolyte contained in the electrode.

[0043] Within the positive electrode mixture layer (positive electrode mixture layer), if the positive electrode active material comes into direct contact with the solid electrolyte, the solid electrolyte will oxidize and form a resistive layer, potentially reducing the ionic conductivity within the positive electrode mixture layer. By setting a reaction inhibition layer on the surface of the positive electrode active material to suppress the reaction with the solid electrolyte, direct contact between the positive electrode active material and the solid electrolyte is prevented, thereby suppressing the reduction in ionic conductivity within the positive electrode mixture layer caused by the oxidation of the solid electrolyte.

[0044] The reaction inhibition layer can be made of any material that has ion conductivity and can inhibit the reaction between the positive electrode active material and the solid electrolyte. Examples of materials that can constitute the reaction inhibition 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, examples include Nb-containing oxides such as LiNbO3, Li3PO4, Li3BO3, Li2SO4, Li4SiO4, Li4GeO4, LiTiO3, LiZrO3, and Li2WO4. The reaction inhibition layer may contain only one of these oxides, or it may contain two or more, and multiple oxides can form a composite compound. Among these oxides, Nb-containing oxides are preferred, and LiNbO3 is more preferred.

[0045] The reaction inhibition layer is preferably present on the surface at a concentration of 0.1 to 1.0 parts by mass relative to 100 parts by mass of the positive electrode active material. If it is within this range, the reaction between the positive electrode active material and the solid electrolyte can be effectively inhibited.

[0046] Methods for forming a reaction-inhibiting layer on the surface of a positive electrode active material include sol-gel method, mechanical fusion method, CVD method, PVD method, ALD method, etc.

[0047] From the viewpoint of further increasing the energy density of all-solid-state batteries using electrodes as positive electrodes, the content of positive electrode active material in the positive electrode mixture is preferably 60 to 85% by mass.

[0048] The positive electrode mixture may contain conductive additives. Specific examples include carbon materials such as graphite (natural graphite, artificial graphite), graphene, carbon black, carbon nanofibers, and carbon nanotubes. It should be noted that, for example, when Ag₂S is used as the active material, conductive Ag is generated during the discharge reaction, so the positive electrode mixture may not contain conductive additives. When the positive electrode mixture contains conductive additives, if the content of the positive electrode active material is set to 100 parts by mass, its content is preferably 1.0 parts by mass or more, preferably 7.0 parts by mass or less, and more preferably 6.5 parts by mass or less.

[0049] In addition, the positive electrode mixture may contain a binder. Specific examples include fluoropolymers such as polyvinylidene fluoride (PVDF). It should be noted that the positive electrode mixture contains a sulfide-based solid electrolyte; however, if good formability can be ensured in forming the positive electrode mixture layer even without the use of a binder due to the action of this sulfide-based solid electrolyte, the positive electrode mixture may not contain a binder.

[0050] When a binder is required in the positive electrode mixture, its content is preferably 15% by mass or less, and more preferably 0.5% by mass or more. On the other hand, when the positive electrode mixture can be molded even without a binder, its content 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., it does not contain a binder).

[0051] The positive electrode mixture contains a sulfide-based solid electrolyte. Examples of sulfide-based solid electrolytes include Li₂S-P₂S₅, Li₂S-SiS₂, Li₂S-P₂S₅-GeS₂, and Li₂S-B₂S₃ glass particles. In addition, thio-LISICON-type materials (composed of Li₂S₅ and Li₂S₅) have attracted considerable attention in recent years due to their high Li-ion conductivity. 10 GeP2S 12 Li 9.54 Si 1.74 P 1.44 S11.7 Cl 0.3 Examples, derived from the general formula Li 12-12a-b+c+6d-e M 1 3+a-b-c-d M 2 b M 3 c M 4 d M 5 12-e X e (where M) 1 For Si, Ge, or Sn, M 2 For P or V, M 3 For Al, Ga, Y, or Sb, M 4 For Zn, Ca, or Ba, M 5 Solid electrolytes (where S is any one of S and O, X is F, Cl, Br or I, 0≤a<3, 0≤b+c+d≤3, 0≤e≤3) and substances with a sulfogermanium-type crystal structure (sulfogermanium-type solid electrolytes).

[0052] Among these solid electrolytes, sulfide-based solid electrolytes containing Li and P are preferred from the perspective of high lithium-ion conductivity, and silver sulfide-germanium ore-type solid electrolytes are even more preferred because they have higher lithium-ion conductivity and higher chemical stability.

[0053] As a sulfide-germanium ore type solid electrolyte, substances represented by the following general formula (1), the following general formula (2) or the following general formula (3) are particularly preferred, for example, Li6PS5Cl.

[0054] Li 7-k PS 6-k X k (1)

[0055] In the above general formula (1), X represents one or more halogen elements, 0.2 <k<2.0。

[0056] Li 7-x+y PS 6-x Cl x+y (2)

[0057] In the above general formula (2), 0.05≤y≤0.9, -3.0x+1.8≤y≤-3.0x+5.7.

[0058] Li 7-a PS 6-a Cl b Br c (3)

[0059] In the above general formula (3), a = b + c, 0 < a ≤ 1.8, 0.1 ≤ b / c ≤ 10.0.

[0060] In addition, the positive electrode mixture may also contain other solid electrolytes together with the sulfide-based solid electrolyte. Examples of the solid electrolyte that can be contained in the positive electrode mixture together with the sulfide-based solid electrolyte include hydride-based solid electrolytes, halide-based solid electrolytes, oxide-based solid electrolytes, and the like.

[0061] Examples of the hydride-based solid electrolyte include LiBH4, a solid solution of LiBH4 and the following alkali metal compounds (for example, a substance with a molar ratio of LiBH4 to the alkali metal compound of 1:1 to 20:1), and the like. Examples of the alkali metal compound in the above solid solution include 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.

[0062] Examples of the halide-based solid electrolyte include monoclinic LiAlCl4, defective spinel-type or layered-structured LiInBr4, monoclinic Li 6-3m Y m X6 (where 0 < m < 2 and X = Cl or Br), etc. In addition, publicly known substances described in, for example, International Publication No. 2020 / 070958 and International Publication No. 2020 / 070955 can also be used.

[0063] Examples of the oxide-based solid electrolyte include garnet-type Li7La3Zr2O 12 , NASICON-type Li 1+ O Al 1+O Ti 2-O (PO4)3, Li 1+p Al 1+p Ge 2-p ] (PO4)3, perovskite-type Li 3q La 2 / 3-q TiO3, and the like.

[0064] From the viewpoint of reducing the grain boundary resistance, the average particle diameter of the solid electrolyte is preferably 0.1 μm or more, more preferably 0.2 μm or more. On the other hand, from the viewpoint of sufficiently forming a contact interface between the active material and the solid electrolyte, it is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 1 μm or less.

[0065] From the viewpoint of further improving the ion conductivity within the positive electrode and further enhancing the output characteristics of the all-solid-state battery, when the content of the positive electrode active material is set to 100 parts by mass, the content of the solid electrolyte in the positive electrode mixture is preferably 10 parts by mass or more, more preferably 15 parts by mass or more. However, if the amount of solid electrolyte in the positive electrode mixture is too large, the amount of other components will decrease, raising concerns that their effects will be diminished. Therefore, when the content of the positive electrode active material is set to 100 parts by mass, the content of the solid electrolyte in the positive electrode mixture is preferably 65 parts by mass or less, more preferably 60 parts by mass or less.

[0066] In addition, when the positive electrode mixture contains sulfide-based solid electrolytes and other solid electrolytes, the content of sulfide-based solid electrolytes in the total content of solid electrolytes in the positive electrode mixture is preferably 20% by mass or more, more preferably 70% by mass or more, and may also be 100% by mass.

[0067] In the case where the electrode is the negative electrode of an all-solid-state battery, the compound (negative electrode compound) contains the negative electrode active material and the sulfide-based solid electrolyte.

[0068] Examples of anode active materials include carbon materials such as graphite, lithium titanium oxides (such as lithium titanate), elemental compounds (oxides, etc.) containing elements such as Si and Sn, and their alloys. Additionally, lithium metal and lithium alloys (lithium-aluminum alloys, lithium-indium alloys, etc.) can also be used as anode active materials.

[0069] From the viewpoint of further increasing the energy density of all-solid-state batteries using electrodes as negative electrodes, the content of negative electrode active material in the negative electrode mixture is preferably 40 to 80% by mass.

[0070] The negative electrode mixture may contain a conductive additive. Specific examples include conductive additives similar to those previously exemplified as being contained in the positive electrode mixture. When the content of the negative electrode active material is set to 100 parts by mass, the content of the conductive additive in the negative electrode mixture is preferably 10 to 30 parts by mass.

[0071] Furthermore, the negative electrode mixture may contain a binder. As a specific example, the same binder previously exemplified as that which can be contained in the positive electrode mixture can be cited. It should be noted that the negative electrode mixture contains a sulfide-based solid electrolyte; however, if good formability in forming the mixture layer (negative electrode mixture layer) can be ensured through the action of this sulfide-based solid electrolyte, the negative electrode mixture may not contain a binder.

[0072] In the negative electrode binder, if an adhesive is required, its content is preferably 15% by mass or less, and more preferably 0.5% by mass or more. On the other hand, in the negative electrode binder, if moldability can be obtained even without an adhesive, its content 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., it does not contain an adhesive).

[0073] The negative electrode mixture contains a sulfide-based solid electrolyte. Specific examples include sulfide-based solid electrolytes similar to those previously exemplified as being contained in the positive electrode mixture. Among the sulfide-based solid electrolytes exemplified above, from the perspective of high lithium-ion conductivity, sulfide-based solid electrolytes containing Li and P are preferred, and argentite-germanium sulfide-type solid electrolytes are more preferred because they have even higher lithium-ion conductivity and higher chemical stability. Solid electrolytes represented by the above general formula (1), general formula (2), or general formula (3) are further preferred.

[0074] In addition, the negative electrode mixture may also contain other solid electrolytes along with the sulfide-based solid electrolyte. Examples of solid electrolytes that can be contained in the negative electrode mixture along with the sulfide-based solid electrolyte include substances that are the same as the various hydride-based solid electrolytes, halide-based solid electrolytes, and oxide-based solid electrolytes previously exemplified as substances that can be contained in the positive electrode mixture.

[0075] For the same reasons as with 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 preferably 10 μm or less, more preferably 5 μm or less.

[0076] From the viewpoint of further improving the ion conductivity within the negative electrode and further enhancing the output characteristics of the all-solid-state battery, when the content of the negative electrode active material is set to 100 parts by mass, the content of the solid electrolyte in the negative electrode mixture is preferably 30 parts by mass or more, more preferably 35 parts by mass or more. However, if the amount of solid electrolyte in the negative electrode mixture is too large, the amount of other components will decrease, raising concerns that their effects will be diminished. Therefore, when the content of the negative electrode active material is set to 100 parts by mass, the content of the solid electrolyte in the negative electrode mixture is preferably 130 parts by mass or less, more preferably 110 parts by mass or less.

[0077] In addition, when the negative electrode mixture contains sulfide-based solid electrolytes and other solid electrolytes, the content of sulfide-based solid electrolytes in the total content of solid electrolytes in the negative electrode mixture is preferably 20% by mass or more, more preferably 70% by mass or more, and may also be 100% by mass.

[0078] The thickness of the compound in the electrode (the thickness of the compound layer) is preferably 0.2 mm or more, more preferably 0.5 mm or more, and even more preferably 0.7 mm or more. On the other hand, it is preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1.5 mm or less.

[0079] The electrode has a current collector made of an alloy containing Ni and Cr. From the viewpoint of improving the conductivity of the current collector and reducing the resistance of the electrode, 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.

[0080] Furthermore, from the viewpoint of suppressing corrosion of the current collector caused by reactions with sulfide-based solid electrolytes and reactions with gases generated from such sulfide-based solid electrolytes, and suppressing the increase in electrode resistance over time, the Cr content in the aforementioned alloy is 0.1% by mass or more, preferably 3% by mass or more, and more preferably 10% by mass or more. However, if the Cr content in the aforementioned alloy is too high, there is a concern that the conductivity of the current collector will decrease and the electrode resistance will increase. Therefore, the Cr content in the aforementioned alloy is 40% by mass or less, preferably 30% by mass or less, and more preferably 20% by mass or less.

[0081] It should be noted that, as can be seen from the Ni and Cr contents in the alloy constituting the current collector described above, the alloy composition of the current collector typically contains Cr with the balance being Ni. However, it can also contain elements other than Ni and Cr (such as Sn, Fe, Co, Ti, Al, Mo, etc.) in a total content of less than 39.9% by mass. That is, in the composition of the alloy constituting the current collector, the total Ni and Cr content is 60.1% by mass or more, and elements other than Ni and Cr can be included in the range of less than 39.9% by mass.

[0082] In addition to foils made of the aforementioned alloys, the current collector can also be made of porous metal substrates such as perforated metal, mesh, expanded metal, and foamed metal. The thickness of the current collector varies depending on the type, but is preferably 10 μm or more in the case of foil, 50 μm or more in the case of perforated metal, mesh, or expanded metal, and 100 μm or more in the case of foamed metal substrates such as foamed metal. Furthermore, the thickness of the current collector is preferably 50 μm or less in the case of foil, 300 μm or less in the case of perforated metal, mesh, or expanded metal, and 3000 μm or less in the case of foamed metal substrates such as foamed metal.

[0083] In such current collectors, porous metal substrates are preferred for higher current collection efficiency, and foamed metal substrates (such as "Celmet" (registered trademark) manufactured by Sumitomo Electric Industries, Ltd.) are even more preferred. When the current collector is made of a porous metal substrate, at least a portion of the binder (binder layer) penetrates into the pores, thereby improving the adhesion between the current collector and the binder. Furthermore, when the current collector is made of a foamed metal substrate, the contact area between the current collector and the binder layer becomes larger, thus further reducing the electrode resistance.

[0084] That is, the electrode preferably has a foamed metal substrate as a current collector, and at least a portion of the compound fills the pores of the foamed metal substrate. More specifically, the foamed metal substrate serving as the current collector of the electrode preferably has at least a portion of its end including the compound layer side embedded in the surface portion of the compound layer and thus integrated with the compound layer.

[0085] It should be noted that such foamed metal substrates are typically compressed and their thickness reduced during electrode fabrication together with the additive. Therefore, the thickness before being used in the electrode is greater than the thickness within 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, particularly preferably 0.5 mm or more, and on the other hand, preferably 3 mm or less, more preferably 2 mm or less, and particularly preferably 1.5 mm or less. For example, in the electrode laminate manufacturing method described later, the foamed metal substrate is compressed in the thickness direction during the electrode fabrication process involving pressurizing the additive and the metal substrate, and its thickness is the value described later.

[0086] Regarding the porosity of the foamed metal substrate before compression, for example, in the process of pressurizing the foamed metal substrate and the additive, in order to facilitate the additive filling into the pores of the metal substrate and to facilitate the integration of the metal substrate and the additive layer, it is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more. On the other hand, in order to improve the conductivity by having a certain volume of the foamed metal substrate, its porosity is preferably 99.5% or less, more preferably 99% or less, and even more preferably 98.5% or less.

[0087] Furthermore, from the viewpoint of adjusting the porosity to an appropriate range, the weight per unit area of ​​porous metal substrates (especially foamed metal substrates) is preferably 600 g / m². 2 The following is more preferably 400g / m 2 The following should be noted: If the weight per unit area of ​​the porous metal substrate (especially the foamed metal substrate) is too small, the resistance of the current collector will increase. Therefore, its weight per unit area is preferably 200 g / m². 2 The above, more preferably 300g / m 2 above.

[0088] Furthermore, for the same reasons mentioned above, the density of the foamed metal substrate (including the apparent density calculated based on the volume of the pores) is preferably 0.22 g / cm³. 3 In addition, the preferred value is 0.66 g / cm³. 3 the following.

[0089] Furthermore, when the current collector has a foamed metal substrate, and the metal substrate is an electrode integral with the adhesive layer by embedding at least a portion of its end containing the adhesive layer in the surface portion of the adhesive layer, from the viewpoint of making the metal substrate and the adhesive layer more reliably integrated, the thickness of the portion of the foamed metal substrate embedded in the adhesive layer is preferably 10% or more of the thickness of the metal substrate (the overall thickness of the foamed metal substrate and the thickness of the portion containing the adhesive layer. Unless otherwise specified, the thickness of the foamed metal substrate is the same below). More preferably, it is 20% or more.

[0090] In an electrode that serves as a current collector and has a foamed metal substrate, at least a portion of the end portion of the additive layer containing the metal substrate is embedded in the surface portion of the additive layer and integrated with the additive layer, in order to reduce the resistance when in contact with the conductive path (described in detail later) in the outer casing of the all-solid-state battery, it is desirable that the end portion opposite to the additive layer portion of the foamed metal substrate (hereinafter sometimes referred to as the surface-side end portion) is not embedded in the additive layer, and the end portion of the electrode (the surface of the electrode) is composed only of the metal substrate. That is, for example, in the electrode stack manufacturing method described later, when manufacturing the electrode by pressurizing the additive and the foamed metal substrate, it is desirable that the metal substrate be compressed in the thickness direction, and the pores at the surface-side end portion of the metal substrate be flattened and disappear, so that only the metal substrate is exposed on the surface of the electrode. However, a portion of the pores at the surface end of the foamed metal substrate can remain as pores without being flattened, thus remaining filled with the adhesive. This allows a portion of the adhesive to be exposed on the electrode surface along with the surface end of the metal substrate, without significantly affecting the contact resistance with the conductive path. In other words, as long as the surface end of the foamed metal substrate is exposed on the electrode surface, the entire metal substrate (100% of the thickness of the foamed metal substrate) can be embedded in the surface portion of the adhesive layer. By filling the pores of the foamed metal substrate with the adhesive until it reaches the electrode surface, the integration of the adhesive with the metal substrate becomes more reliable.

[0091] Figure 1 The image shown is a scanning electron microscope (SEM) image illustrating the surface state of an electrode with a foamed metal substrate as a current collector. (It should be noted that...) Figure 1The SEM images shown are not images of the surface of the electrode of the present invention, but rather images of an electrode having the same surface condition as the electrode of the present invention (corresponding to the electrode of Comparative Example 1 described later), and are shown only for the purpose of illustrating the surface condition of the electrode of the present invention. Figure 1 In the electrode surface shown, the end of the foamed metal substrate 122 of the electrode is exposed, but a portion of the compound 121a is also exposed on the surface of the electrode by entering the pores present at the end of the metal substrate.

[0092] However, the greater the proportion (area ratio) of the compound exposed on the surface of the electrode, the greater the contact resistance between the foamed metal substrate and the conductive path of the all-solid battery. Therefore, the proportion of the area of ​​the exposed compound on the surface of the electrode is preferably 50% or less, more preferably 25% or less, further preferably 15% or less, and particularly preferably 10% or less when viewed from above.

[0093] In an electrode having a foamed metal substrate as a current collector, when at least a portion of the metal substrate is embedded in the surface portion of the binder layer, from the viewpoint of more reliably integrating the metal substrate and the binder layer, the thickness of the foamed metal substrate is preferably 1% or more, more preferably 2% or more, and particularly preferably 3% or more, of the overall thickness of the binder layer (including the thickness of the portion coexisting with the foamed metal substrate. Unless otherwise specified, the "thickness of the binder layer" referred to below means the "overall thickness of the binder layer" as described herein). Furthermore, from the viewpoint of improving the filling properties of the binder layer in the electrode, the thickness of the foamed metal substrate is preferably 30% or less, more preferably 20% or less, and particularly preferably 10% or less, of the thickness of the binder layer.

[0094] It should be noted that in the electrode having a foamed metal substrate as a current collector, the thickness of the foamed metal substrate (the thickness after electrode forming) is preferably 10 μm or more, more preferably 20 μm or more, particularly preferably 30 μm or more, and on the other hand, preferably 300 μm or less, more preferably 200 μm or less, and particularly preferably 100 μm or less.

[0095] The thickness of the foamed metal substrate and the thickness of the compound layer in the electrode are determined by the maximum value of the width in the thickness direction of the regions where the foamed metal substrate and the compound layer can be identified, respectively, in cross-sectional images of the electrode viewed at SEM magnification of 50 to 1000x. Furthermore, the thickness of the portion of the foamed metal substrate embedded in the compound layer is determined by the maximum value of the width in the thickness direction of the overlapping portion between the regions where the metal substrate and the compound layer can be identified (the values ​​in the embodiments described later are values ​​obtained using these methods).

[0096] In addition, the proportion (area ratio) of the compound exposed on the surface of the electrode is determined by the ratio (A / B) of the total area A of the exposed portion to the total area B of the electrode in an image of the electrode surface observed by SEM at a magnification of 50 to 200 (the values ​​in the embodiments described later are obtained by this method).

[0097] Electrodes can be manufactured by molding the compound into a pressurized compound (particles, etc.) and bonding it to a current collector, or by pressing the compound and the current collector at one time while simultaneously molding the compound and integrating it with the current collector, or by coating the current collector with a compound-containing composition in which the compound is dispersed in a solvent and drying it, followed by a pressurization process as needed.

[0098] The solvent for the above-mentioned compound composition is preferably a solvent that is unlikely to degrade the solid electrolyte. In particular, since sulfide-based and hydride-based solid electrolytes undergo chemical reactions through trace amounts of water, nonpolar and aprotic solvents, such as hydrocarbon solvents like hexane, heptane, octane, nonane, decane, decahydronaphthalene, toluene, and xylene, are preferred. In particular, ultra-dehydrating solvents with a water content of 0.001% by mass (10 ppm) or less are more preferred. In addition, fluorinated solvents such as "Burrel (registered trademark)" manufactured by Mitsui-DuPont Fluorochemicals, "ZEORORA (registered trademark)" manufactured by Zeon Corporation, and "Novec (registered trademark)" manufactured by Sumitomo 3M, as well as non-aqueous organic solvents such as dichloromethane and diethyl ether, can also be used.

[0099] All-solid-state batteries

[0100] The all-solid-state battery of the present invention has 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 the all-solid-state battery of the present invention. It should be noted that the all-solid-state battery of the present invention can be manufactured into a secondary battery (all-solid-state secondary battery) or a primary battery (all-solid-state primary battery) by selecting the electrode composition (active material, etc.).

[0101] The positive and negative electrodes are used in an all-solid-state battery, for example, in the form of an electrode stack consisting of layers separated by a solid electrolyte layer. The electrode stack is then encapsulated in an outer casing to form an all-solid-state battery.

[0102] Figure 2 The diagram shows a schematic longitudinal cross-sectional view illustrating an example of the all-solid-state battery of the present invention. Figure 2The all-solid-state battery 100 shown is configured to have an electrode stack 110 which is sealed inside a battery container (outer body) formed by a concave container 150 and a sealing body 160. The electrode stack 110 has a positive electrode 120, a negative electrode 130 and a solid electrolyte layer 140 between them.

[0103] The schematic representation constitutes Figure 2 A perspective view of the concave container 150 of the battery container of the all-solid-state battery 100 shown in the figure. Figure 3 .like Figure 3 As shown, the concave container 150 is composed of a bottom part 151 and a side wall part 152, and the cross-section of the opening part with the upper opening in the figure is concave.

[0104] Figure 2 The battery 100 shown is an example having a positive electrode 120 and a negative electrode 130. The positive electrode 120 has a foamed metal substrate 122 as a current collector, and the negative electrode 130 has a foamed metal substrate 132 as a current collector. That is, the positive electrode 120 has a positive electrode binder layer 121 and a foamed metal substrate 122, and the entire foamed metal substrate 122, including the end on the positive electrode binder layer 121 side, is embedded in the surface portion of the positive electrode binder layer 121. That is, the entire area where the foamed metal substrate 122 exists corresponds to the area where the positive electrode binder layer and the foamed metal substrate coexist. Furthermore, in the positive electrode 120, the end on the side opposite to the positive electrode binder layer 121 side of the foamed metal substrate 122 ( Figure 2 The lower end is exposed. It should be noted that the dashed line in the positive electrode 120 represents the boundary between the area in the positive electrode mixture layer 121 where the foamed metal substrate does not coexist and the area where the positive electrode mixture layer coexists with the foamed metal substrate, which is equivalent to the end of the foamed metal substrate 122 on the positive electrode mixture layer 121 side.

[0105] Furthermore, the negative electrode 130 has a negative electrode mixture layer 131 and a foamed metal substrate 132, the entire foamed metal substrate 132, including the end facing the negative electrode mixture layer 131, is embedded in the surface portion of the negative electrode mixture layer 131. That is, the entire area where the foamed metal substrate 132 exists corresponds to the region where the negative electrode mixture layer and the foamed metal substrate coexist. Furthermore, in the negative electrode 130, the end of the foamed metal substrate 132 on the opposite side to the negative electrode mixture layer 131 side (… Figure 2 The upper end is exposed. It should be noted that the dashed line in the negative electrode 130 represents the boundary between the area in the negative electrode mixture layer 131 where the foamed metal substrate does not coexist and the area where the negative electrode mixture layer coexists with the foamed metal substrate, which is equivalent to the end of the foamed metal substrate 132 on the negative electrode mixture layer 131 side.

[0106] A connection terminal portion 170, 180 for electrical connection with a device used in the all-solid-state battery 100 is provided on the lower side of the concave container 150. Furthermore, the connection terminal portion 170 is electrically connected to a conductive path 171 extending from the inside of the concave container 150 to the outside. The conductive path 171 is electrically connected to the positive electrode 120 of the electrode stack 110 housed in the concave container 150, thereby establishing a connection between the positive electrode 120 of the electrode stack 110 and the connection terminal portion 170. It should be noted that... Figure 2 In the all-solid-state battery 100, a porous metal substrate 190, which is the same as the porous metal substrate used for the current collector, is sandwiched between the positive electrode 120 and the conductive path 171 of the electrode stack 110 as a conductive connection member. Through the action of the porous metal substrate 190, the conductivity between the positive electrode 120 and the conductive path 171 can be improved. In addition, the generation of deviation in the internal resistance of each battery in the case of manufacturing multiple all-solid-state batteries can be suppressed (details will be described later).

[0107] Furthermore, the connecting terminal portion 180 is electrically connected to the conductive path 181 of the connecting terminal portion 180, which extends from the inside of the concave container 150 to the outside. This conductive path 181 is disposed in the upper part of the electrode laminate 110 and is electrically connected to the negative electrode 130 via an elastic conductive member 210 that contacts the negative electrode 130 of the electrode laminate 110. Thus, the negative electrode 130 of the electrode laminate 110 is connected to the connecting terminal portion 180.

[0108] The concave container 150 has a support portion 153 for supporting the elastic conductive member 210 on its sidewall 152. In the all-solid-state battery 100, such as... Figure 3 As shown, the support portion 153 is formed at the upper end of the inner peripheral surface of the sidewall portion 152 and extends radially. However, the support portion used to hold the elastic conductive component of the all-solid-state battery can also be of other shapes as long as it can support the elastic conductive component 210.

[0109] in addition, Figure 4 The illustration shows a schematic representation. Figure 2 The diagram shows a perspective view of the elastic conductive component 210 of the all-solid-state battery 100. The elastic conductive component 210 is, for example, made of a thin metal plate, such as... Figure 4 As shown, it has a quadrilateral shape when viewed from above, but it can be set to a shape that corresponds to the top view shape of the electrode stack and concave container of an all-solid-state battery.

[0110] Figure 2The concave container 150 of the all-solid-state battery 100 shown has a plurality of support portions 153 for supporting the elastic conductive members 210 at the upper end of its sidewall portion 152. The support portions 153 are formed as protrusions that project circumferentially onto the inner circumferential surface of the sidewall portion 152. More specifically, the support portions 153 are a plurality of recessed top walls formed radially outward on the inner circumferential surface of the sidewall portion 152. Furthermore, a portion of the conductive path 181 is exposed on the lower surface and side surface of the top wall. The support portions 153 are formed with at least a number corresponding to the number of supported portions 211 of the elastic conductive members 210 described later.

[0111] The elastic conductive member 210 has a supported portion 211 and a planar portion 212. The supported portions 211 are located radially outward when viewed from above in the electrode stack 110 of the all-solid-state battery 100, and multiple such portions are provided corresponding to the positions of the supported portions 153. The supported portions 211 are hook-shaped locking tabs that engage with the lower surface of the top wall of the supported portion 153, extending from the edge of the elastic conductive member 210 toward the supported portion 153. Figure 2 (The support portion 211 extends below the support portion 153). Furthermore, the supported portion 211 has a front end that folds back towards the lower surface of the support portion 153, i.e., the top wall. The front end of the supported portion 211 contacts the conductive path 181 exposed on the lower surface and side of the top wall of the support portion 153. Thus, the elastic conductive member 210 functions as a current collector, becoming part of the conductive path that electrically connects the negative electrode 130 to the connection terminal portion 180.

[0112] The elastic conductive member 210 is supported by a support portion 153 formed on the inner peripheral surface of the side wall portion 152 of the concave container 150, covering a portion of the opening of the concave container 150. The area of ​​the elastic conductive member 210 in top view is smaller than the opening area of ​​the concave container 150. It should be noted that even if the hook-shaped locking piece of the elastic conductive member 210 does not engage with the lower surface of the top wall of the support portion 153, as long as the elastic conductive member 210 is fixed in the state where the hook-shaped locking piece is pressed into the recess formed on the inner peripheral surface of the side wall portion 152, the elastic conductive member 210 will still be engaged with the side wall portion 152 of the concave container 150.

[0113] like Figure 2 and Figure 4 As shown, the elastic conductive member 210 has a spring portion 213 that rises from the planar portion 212 toward the negative electrode 130 of the electrode stack 110. The spring portion 213 contacts the upper surface of the negative electrode 130 (its porous metal substrate 132) of the electrode stack 110 and presses the electrode stack 110 toward the inner bottom surface of the concave container 150.

[0114] In an elastic conductive component with a spring section, the shape of the spring section is not particularly limited as long as it can press the electrode stack toward the inner bottom surface of the concave container. Figure 2and Figure 4 The elastic conductive member 210 shown has a spring portion 213 that is a spring sheet inclined from the planar portion 212 toward the negative electrode 130 of the electrode stack 110 (hereinafter, the spring portion 213 is sometimes referred to as the spring sheet 213). Figure 4 As shown, the spring sheet 213 is formed by cutting a portion of the flat portion 212 into a U-shape, and is cantilevered on the flat portion 212. That is, Figure 2 and Figure 4 The spring sheet 213 in the elastic conductive component 210 shown is a leaf spring. If the elastic conductive component 210 is of this type, the spring sheet 213 only needs to be formed on a portion of the flat portion 212, thus making it easier to manufacture the elastic conductive component and, consequently, the all-solid-state battery. Furthermore, by cutting away the flat portion 212 to form the spring sheet 213, it is even easier to manufacture the elastic conductive component and, consequently, the all-solid-state battery.

[0115] The spring sheet 213 has a boundary 213a and a front end portion 213b that are in contact with the planar portion 212. In order to contact the negative electrode 130 of the electrode stack 110, it is bent at the boundary 213a and tilted towards the electrode stack 110 from the boundary 213a toward the front end portion 213b. However, if the front end portion 213b of the spring sheet 213 is brought into contact with the negative electrode 130 of the electrode stack 110, there is a concern that the negative electrode 130 may be damaged by the front end portion 213b. Therefore, in... Figure 2 and Figure 4 In the elastic conductive component 210 shown, the spring sheet 213 is oriented towards the front end 213b. Figure 2 The spring sheet 213 is bent in the upper middle direction, and the portion of the spring sheet 213 other than the front end 213b contacts the negative electrode 130.

[0116] In the elastic conductive member 210 before the assembly of the all-solid-state battery 100, the height from the bottom surface of the planar portion 212 to the point where the spring sheet 213 contacts the negative electrode 130 (the height of the spring sheet 213) is greater than the height from the bottom surface of the planar portion 212 to the point where it contacts the negative electrode 130 in the elastic conductive member 210 after the assembly of the all-solid-state battery 100. Therefore, the spring sheet 213 can press the electrode stack 110, thereby maintaining a good electrical connection between the elastic conductive member 210 and the negative electrode 130 of the electrode stack 110.

[0117] Furthermore, in the elastic conductive member 210, by forming the spring portion 213 with a spring sheet, the thickness of the elastic conductive member 210, excluding the supported portion 211, can be reduced. 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 set to the sum of the thickness of the plate constituting the planar portion 212 and the height of the spring sheet 213. Specifically, the thickness of the plate (0.2 mm) and the height of the spring sheet (0.5 mm) can be added together to set the thickness of the elastic conductive member 210, excluding the supported portion 211, to 0.7 mm.

[0118] Furthermore, regarding the spring sheet 213, its length (the length from the boundary 213a to the front end 213b) can be set to 3 mm, etc., and its width (the length in the direction orthogonal to the aforementioned length direction) can be set to 1.5 mm, etc. It should be noted that multiple spring sheets can be provided in the elastic conductive member having the spring sheet. In this case, for reasons such as preventing resonance, the shape, including the width and length of the spring sheet, can be different. 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 for the spring portion 213 to generate pressing force effectively, 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.

[0119] 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 portion of the spring sheet 213 that contacts the negative electrode 130 will not increase. As a result, the increase of the gap between the sealing body 160 and the electrode stack 110 can be suppressed, thus enabling a high-capacity all-solid-state battery 100. It should be noted that the thickness direction of the elastic conductive member 210 refers to... Figure 2 The vertical direction (the height direction of the all-solid-state battery 100) can also be described as the direction orthogonal to the bottom surface of the planar part 212.

[0120] The overall thickness of the elastic conductive member 210, including the supported portion 211, can be appropriately set according to the height of the side wall portion 152 of the concave container 150 from the bottom portion 151. Furthermore, the supported portion 211 only needs to have the height required to engage with the support 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.

[0121] In the elastic conductive component 210, the spring sheet 213 can be formed by cutting open the planar portion 212 as described above, or it can be mounted by welding the spring sheet 213 onto the bottom surface of the planar portion 212. Alternatively, a base for mounting the spring sheet 213 can be provided separately from the planar portion 212 beforehand, and the spring sheet 213 can be mounted on the base to form the entire spring portion. That is, the spring sheet 213 can be erected directly from the planar portion 212, or it can be erected from the planar portion 212 with other elements such as the base in between. Furthermore, the spring sheet 213 can also be supported on the planar portion 212 in a shape that protrudes toward the electrode laminate 110.

[0122] exist Figure 2 In the all-solid-state battery 100 shown, when the elastic conductive member 210 is provided, firstly, the electrode stack 110 is housed inside the concave container 150, and then 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 front end of the supported portion 211 is positioned along the axial direction of the electrode stack 110. Figure 2 The elastic conductive member 210 is positioned between the upper surface of the electrode stack 110 and the lower surface of the support portion 153 (i.e., the top wall) in the vertical direction. Then, while pressing the supported portion 211 of the elastic conductive member 210 towards the bottom portion 151 of the concave container 150, the supported portion 211 is supported on the support portion 153. More specifically, the front end of the supported portion 211 is engaged with the lower surface of the support portion 153 (i.e., the top wall). As the supported portion 211 is pressed downwards, the spring sheet 213 of the elastic conductive member 210, while in contact with the electrode stack 110, presses in the opposite direction to the negative electrode 130. At this time, the spring sheet 213 presses the electrode stack 110 towards the bottom portion 151 of the concave container 150 by its elastic force. Therefore, the elastic conductive member 210 and the electrode stack 110 are in more stable contact, and there is no positional shift due to vibration or other factors, thus maintaining a good electrical connection.

[0123] exist Figure 2 In the all-solid-state battery 100 shown, the concave container 150 has two support portions 153, 153, but the number of support portions 153 can also be three or more. The supported portion 211 of the elastic conductive member 210 can be formed according to the number of support portions 153.

[0124] It should be noted that, as a method for fixing the edge (supported by the support 211) of the elastic conductive member 210 to the inner peripheral surface of the side wall portion 152 of the concave container 150, another example is a method for bonding the edge of the elastic conductive member 210 to the inner peripheral surface of the side wall portion 152 of the concave container 150.

[0125] It should be noted that, as Figure 2 As shown, a gap is preferably formed between the elastic conductive member 210 and the sealing body 160. That is, it is preferable that the elastic conductive member 210 and the sealing body 160 do not contact each other. Thus, even if the elastic conductive member 210 is pressed towards the sealing body 160 due to the volume change of the electrode stack 110, contact between the elastic conductive member 210 and the sealing body 160 can be avoided.

[0126] exist Figure 2 In the all-solid-state battery 100 shown, the electrode stack 110 is arranged such that the positive electrode 120 is located on the inner bottom surface side of the concave container 150 and the negative electrode 130 is located on the sealing body 160 side (elastic conductive member 210 side). However, the electrode stack can also be arranged such that the negative electrode is located on the inner bottom surface side of the concave container and the positive electrode is located on the sealing body side (elastic conductive member side) to form an all-solid-state battery.

[0127] (electrode)

[0128] In the all-solid-state battery of the present invention, either the positive electrode or the negative electrode can be an electrode of the present invention, or both the positive electrode and the negative electrode can be electrodes of the present invention.

[0129] In the case where only the positive electrode of the all-solid-state battery has the electrode of the present invention, the negative electrode can be a negative electrode with the same structure as the electrode of the present invention except for the composition of the current collector, a negative electrode with the same structure as the electrode of the present invention except that it does not contain a sulfide-based solid electrolyte but contains a solid electrolyte different from the sulfide-based solid electrolyte, a negative electrode that directly uses lithium metal or lithium-aluminum alloy foil, a negative electrode having lithium metal or lithium-aluminum alloy foil and a current collector, etc.

[0130] In the case where only the negative electrode of the all-solid-state battery has the electrode of the present invention, the positive electrode can be a positive electrode that is the same as the electrode of the present invention except for the composition of the current collector, or a positive electrode that is the same as the electrode of the present invention except that it does not contain a sulfide-based solid electrolyte but contains a solid electrolyte that is different from a sulfide-based solid electrolyte.

[0131] It should be noted that, in the positive and negative electrodes of an all-solid-state secondary battery, the positive electrode is more prone to corrosion of the current collector. Therefore, from the viewpoint of better ensuring the effect of suppressing the increase of the battery's internal resistance, 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 more preferably both the positive and negative electrodes are the electrodes of the present invention.

[0132] (Solid electrolyte layer)

[0133] Specific examples of solid electrolytes constituting the solid electrolyte layer of an all-solid-state battery include solid electrolytes that are the same as those previously exemplified as solid electrolytes contained in the positive electrode mixture. Among the solid electrolytes exemplified above, from the perspective of high lithium-ion conductivity and improved formability, sulfide-based solid electrolytes are preferred, sulfide-based solid electrolytes having a sulfide-germanium sulfide crystal structure are more preferred, and solid electrolytes represented by the above general formula (1), general formula (2), or general formula (3) are even more preferred.

[0134] Solid electrolyte layers can be formed by methods such as compressing solid electrolytes through pressure molding; or by coating a solid electrolyte layer forming composition prepared by dispersing solid electrolytes in a solvent onto a substrate, a positive electrode, and a negative electrode, drying it, and then pressing it as needed.

[0135] To maintain its shape, the solid electrolyte layer may contain adhesives such as acrylic resin and fluororesin.

[0136] Alternatively, the solid electrolyte layer can also have a porous material such as a resin-based nonwoven fabric as a support. In this case, a solid electrolyte sheet with the aforementioned support is obtained.

[0137] The solvent used in the composition for forming the solid electrolyte layer should also be selected in the same way as the solvent used in the composition containing the additive, so as to avoid degrading the solid electrolyte. As the solvent for the composition containing the additive, it is preferable to use the various solvents previously exemplified, and it is particularly preferable to use an ultra-dehydrating solvent with a water content of 0.001% by mass (10 ppm) or less.

[0138] The thickness of the solid electrolyte layer is preferably 10~200μm.

[0139] (Manufacturing method of electrode laminate)

[0140] There are no particular limitations on the manufacturing method of the electrode stack used to construct an all-solid-state battery, which uses an electrode stack having a positive electrode, a negative electrode and a solid electrolyte layer in between. For example, it can be manufactured by a manufacturing method having the following first to third steps.

[0141] In the first step, the mixture (positive electrode mixture or negative electrode mixture) is added to a mold and pressurized. The surface pressure of the pressurization in the first step is preferably 30 to 500 MPa.

[0142] In the next second step, a porous metal substrate is placed on the mixture formed under pressure in the first step. In the next third step, the mixture and the porous metal substrate are pressurized. Through the pressurization in this third step, the porous metal substrate is embedded in the mixture from the end on the mixture side, and the mixture is further compressed while the porous metal substrate is compressed in the thickness direction, so that the mixture layer (positive electrode mixture layer or negative electrode mixture layer) and the porous metal substrate are integrated to form an electrode (positive electrode or negative electrode).

[0143] As described above, in this third step, the porous metal substrate is compressed in the thickness direction. However, regarding the degree of compression, from the viewpoint of making the bonding between the porous metal substrate and the adhesive layer more reliable, it is preferable that the thickness of the compressed porous metal substrate 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 improving the bonding strength between the porous metal substrate and the adhesive layer by retaining a certain amount of adhesive within the pores of the porous metal substrate, it is preferable that the thickness of the compressed porous metal substrate in the third step is 1% or more of the thickness before compression, more preferably 2% or more.

[0144] In order to compress the compound and thus fully increase the density of the compound layer, the surface pressure during the pressurization process in the third step is preferably 800 MPa or more, more preferably 1000 MPa or more, and particularly preferably 1200 MPa or more. There is no specific upper limit for the surface pressure during the pressurization process in the third step; in general pressurization devices, around 2000 MPa is typically the upper limit.

[0145] By going through the first to third steps described above, an electrode (positive or negative electrode) can be obtained with the following configuration: at least a portion of the end of the porous metal substrate on the side of the mixture layer (within a certain range in the thickness direction from the end of the porous metal substrate) is embedded in the surface portion of the mixture layer and integrated with the mixture layer, and the other end of the porous metal substrate is exposed on the surface of the electrode.

[0146] It should be noted that if the surface pressure during the pressurization process in the third step is high, cracks may occur when the porous metal substrate is compressed. However, even if it is cut off and fragments are generated, as long as the end is exposed on the surface of the electrode, it can help reduce the contact resistance.

[0147] The positive and negative electrodes are produced through the first, second, and third processes described above. They are then placed on both sides of the solid electrolyte layer and pressurized as needed to form an electrode stack.

[0148] Furthermore, a preparatory step can be set before the first step, in which the solid electrolyte is put into a mold for pressure molding. An additive (positive electrode additive or negative electrode additive) is placed on the solid electrolyte after it has been pressure molded through the preparatory step. Then, the first step, the second step and the third step are carried out in sequence, thereby creating an integrated solid electrolyte layer and an electrode (positive electrode or negative electrode) for use in an electrode laminate.

[0149] The surface pressure during the preparatory process of pressurization is preferably set to 30~120MPa.

[0150] Alternatively, an electrode stack can be manufactured by performing the first, second, and third processes sequentially on the other side of a solid electrolyte layer on which one of the electrodes (positive or negative) is formed, following the preparatory process.

[0151] (outer body)

[0152] The outer casing of a solid-state battery can use a device with Figure 2 The battery containers shown include concave containers (outer containers) and sealing bodies (lids), flat (coin-shaped, button-shaped, etc.) or cylindrical (cylindrical, square, etc.) battery containers with metal outer cans and metal sealing bodies, and battery containers with laminated outer bodies made of metal laminates such as aluminum laminates.

[0153] In having Figure 2 In the case of the battery container with the concave container and the sealing body shown, the concave container can be a container made of ceramic or resin. Additionally, the sealing body can be a sealing body made of ceramic, resin, or metal (iron-based alloys such as iron-nickel alloys and iron-nickel-cobalt alloys).

[0154] In the concave container, the conductive path between the connecting terminal portion, the electrode of the connecting electrode stack, and the connecting terminal portion can be made of metals such as manganese, cobalt, nickel, copper, molybdenum, silver, palladium, tungsten, platinum, and gold, or alloys containing them.

[0155] Concave containers and sealing bodies can be sealed not only by adhesive but also, in the case of metal sealing bodies, such as... Figure 2 As shown, a sealing ring 200 made of metal (such as an iron-nickel alloy, an iron-nickel-cobalt alloy, or other iron-based alloy) can also be disposed on the sealing body 160 side (upper side in the figure) of the side wall portion 152 of the concave container 150. The sealing body side of the side wall portion is made of metal, and the concave container and the sealing body are sealed by welding.

[0156] The top-view shape of the outer casing can be circular, or it can be a polygon such as a quadrilateral (square, rectangle). In the case of a polygon, its corners can also be curved.

[0157] (Elastic conductive component)

[0158] There are no particular limitations on how the elastic conductive component functions as a leaf spring that presses the electrode stack toward the inner bottom surface of the concave container. Specifically, examples include... Figure 2 and Figure 4 The elastic conductive member shown has a supported portion 211 with a shape corresponding to the support portion 153 of the concave container 150 and a flat portion 212 with a spring portion (spring sheet) 213, a locking portion with a shape corresponding to the support portion of the concave container, and an elastic conductive member with a cross-sectional shape of the concave portion of the pressing electrode laminate, etc.

[0159] The elastic conductive component can be formed from a plate made of nickel, iron, copper, chromium, cobalt, titanium, aluminum, or their alloys. In the examples described above, the metal constituting the elastic conductive component is preferably stainless steel or a metal obtained by nickel plating a stainless steel plate. For easier functioning as a leaf spring, spring-grade stainless steels such as SUS301-CSP, SUS304-CSP, SUS316-CSP, SUS420J2-CSP, SUS631-CSP, and SUS632J1-CSP are more preferred.

[0160] To ensure that the pressing pressure on the electrode stack is at least a certain level, 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. On the other hand, to prevent the elastic conductive member from being too thick and thus increasing the housing volume inside the battery container, and to make it easier for the elastic conductive member to deform and easily lock into the side wall 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.

[0161] (Conductive connection component)

[0162] like Figure 2 As shown in the all-solid-state battery, to prevent gaps from forming between the electrode stack and the inner bottom surface of the concave container of the battery case due to variations in the thickness (height) of each component, a conductive connection component is preferably provided to ensure that the conductive connection component is connected to the conductive path of the concave container. That is, when a conductive connection component is provided, the electrodes (on the inner bottom surface side of the concave container in the electrode stack) are connected. Figure 2 The solid-state battery 100 shown has a positive electrode 120 and a conductive path in the concave container. Figure 2In the case of the all-solid-state battery 100 shown, the conductive path is 171 via the conductive connection component ( Figure 2 In the case of the all-solid-state battery shown, a porous metal substrate (190) is used for conduction.

[0163] As a conductive connection component, a porous metal substrate constituting the current collector of the aforementioned electrodes can be exemplified. In particular, the foamed metal substrate is easily plastically deformed by applying force in the thickness direction. Therefore, during the formation of an all-solid-state battery, it is easily compressed and deformed to reduce its thickness according to the degree of deviation (deviation from design value) in the thickness (height) of each component. This allows for good contact between the electrode on the porous metal layer side of the electrode stack and the current collector, and enables homogenization of the conductivity between the porous metal layer and the electrode stack in each of multiple all-solid-state batteries when manufacturing multiple batteries. In all-solid-state batteries, when using a porous metal substrate, especially a foamed metal substrate, these effects further reduce internal resistance and decrease deviations in individual internal resistances.

[0164] As for the foamed metal substrate, the same type of material preferred as the current collector of the electrode is "Celmet (registered trademark)" manufactured by Sumitomo Electric Industries, Ltd.

[0165] From the viewpoint of better ensuring the function of the foamed metal substrate, the thickness of the foamed metal substrate after battery assembly in an all-solid-state battery is preferably 20 μm or more, more preferably 100 μm or more. Furthermore, there is no particular upper limit to the thickness of the foamed metal substrate in an all-solid-state battery; from the viewpoint of suppressing the volume of components inside the battery container that do not participate in power generation, it is preferably 500 μm or less, more preferably 300 μm or less.

[0166] The thickness of the conductive connection component is determined by the maximum value of the width in the thickness direction from a cross-sectional image of its thickness direction observed using SEM at a magnification of 50 to 1000 (the values ​​in the embodiments described below are obtained by these methods).

[0167] It should be noted that, as described above, the conductive connecting component preferably has a porous metal substrate compressed in the thickness direction, and its thickness is preferably 90% or less, more preferably 80% or less, of the thickness of the porous metal substrate used to form the conductive connecting component (thickness before compression). Therefore, the thickness of the porous metal substrate used to form the conductive connecting component is preferably 150 to 3000 μm.

[0168] Furthermore, regarding the porosity (porosity before compression) of the porous metal substrate used to form the conductive connection component, from the viewpoint that it is easier and better to ensure the reduction effect of internal resistance and the suppression effect of deviation of the all-solid battery by plastic deformation caused by pressing the electrode laminate, it is preferably 99.5% or less, more preferably 99% or less, and even more preferably 98.5% or less. From the viewpoint of ensuring sufficient strength in use, it is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more.

[0169] Example

[0170] The present invention will now be described in detail based on embodiments. However, the following embodiments do not limit the present invention.

[0171] (Example 1)

[0172] Lithium titanate (Li4Ti5O) with an average particle size of 2 μm 12 A negative electrode mixture was prepared by mixing a sulfide-based solid electrolyte (Li6PS5Cl) with an average particle size of 0.7 μm and graphene (conductive additive) in a mass ratio of 50:41:9.

[0173] In addition, a positive electrode mixture was prepared by mixing LiCoO2 (positive electrode active material) with an average particle size of 5 μm and a coating layer of LiNbO3 on its surface, a sulfide-based solid electrolyte (Li6PS5Cl) with an average particle size of 0.7 μm, and graphene in a mass ratio of 65:30.7:4.3.

[0174] Next, sulfide-based solid electrolyte (Li6PS5Cl) powder with an average particle size of 0.7 μm is placed into a powder molding die, and pressed using a press at a surface pressure of 70 MPa to form a temporary molding layer for the solid electrolyte layer. Then, the aforementioned negative electrode agent is deposited on the upper surface of the temporary molding layer of the solid electrolyte layer, and pressed at a surface pressure of 50 MPa to further form a temporary molding layer for the negative electrode on the temporary molding layer of the solid electrolyte layer.

[0175] Next, on the temporary molding layer of the negative electrode formed on the temporary molding layer of the solid electrolyte layer, a foamed metal substrate (“Celmet”, a registered trademark) from Sumitomo Electric Industries, Ltd., made of Ni-Cr alloy with Ni and Cr contents of 95% by mass and 5% by mass, is placed on the substrate. The substrate is cut to a diameter of 7.25 mm (thickness: 1.1 mm, porosity: 98%, weight per unit area: 347 g / m²). 2 The substrate is pressurized at 300MPa to form an integrated solid electrolyte layer and negative electrode.

[0176] Then, after the mold is reversed, the positive electrode mixture is placed on the upper surface of the solid electrolyte layer inside the mold (the side opposite to the side with the negative electrode), and pressure is applied at a surface pressure of 50 MPa to form a temporary forming layer of the positive electrode on the solid electrolyte layer.

[0177] Next, on the temporary molding layer of the positive electrode formed on the solid electrolyte layer, a material made of a foamed metal substrate with the same composition as that used in the negative electrode is placed and pressed and molded with a surface pressure of 1400 MPa to obtain an electrode laminate.

[0178] In the obtained electrode stack, the thicknesses of the negative electrode flux layer, the porous metal substrate, and the portion of the porous metal substrate embedded in the negative electrode flux layer are 1400 μm, 60 μm (5% of the thickness of the porous metal substrate before the negative electrode), and 60 μm (100% of the total thickness of the porous metal substrate), respectively. Furthermore, the area percentage of the negative electrode flux exposed on the surface of the negative electrode is 7%.

[0179] Furthermore, in the obtained electrode stack, the thicknesses of the positive electrode flux layer, the porous metal substrate, and the portion of the porous metal substrate embedded in the positive electrode flux layer are 800 μm, 60 μm (5% of the thickness of the porous metal substrate before the positive electrode), and 60 μm (100% of the total thickness of the porous metal substrate), respectively. Additionally, the area percentage of the positive electrode flux exposed on the surface of the positive electrode is 7%.

[0180] In having Figure 2 and Figure 3 The same structure shown, made of ceramic, with a sealing ring of iron-nickel-cobalt alloy on the upper part of the sidewall, is used to insert an object obtained by cutting a foamed Ni metal substrate into a diameter of 7.25 mm into the inner bottom surface of the concave container (ceramic depth 2.5 mm). This object is brought into contact with the conductive path of the positive electrode, and the aforementioned electrode stack is placed on it, with the positive electrode facing down. Furthermore, on the negative electrode of the electrode stack, a stainless steel plate (thickness 0.3 mm) with a sealing ring of iron-nickel-cobalt alloy is placed... Figure 2 and Figure 4The supported portion of the elastic conductive component of the same shape shown is engaged with the support portion of the concave container. Then, the spring sheet of the elastic conductive component is bent towards the negative electrode side of the electrode stack, with its front end facing the flat portion side, so that the spring sheet contacts the negative electrode of the electrode stack at a point closer to the boundary of the flat portion than its front end, thereby pressing the electrode stack towards the inner bottom surface of the concave container. Then, a sealing body made of an iron-nickel-cobalt alloy plate (0.1 mm thick) is placed on the sealing ring of the concave container, and the sealing body is welded to the concave container (sealing ring), thereby sealing the battery container and obtaining an all-solid-state secondary battery. In the obtained all-solid-state secondary battery, as described above, the elastic conductive component presses the electrode stack towards the inner bottom surface of the concave container, thereby pressing the conductive connection component made of a foamed metal substrate. Furthermore, the thickness of the conductive connection component in the all-solid-state secondary battery is 200 μm.

[0181] (Example 2)

[0182] In addition to changing the foamed metal substrate used as the current collector for both the positive and negative electrodes to a substrate composed of a Ni-Cr alloy with Ni and Cr contents of 85% and 15% by mass, respectively (weight per unit area: 388 g / m²), 2 Except for Example 1, an all-solid-state secondary battery was fabricated in the same manner.

[0183] (Example 3)

[0184] In addition to changing the foamed metal substrate used as the positive and negative electrodes to a substrate composed of a Ni-Cr alloy with Ni and Cr contents of 75% and 25% by mass, respectively (weight per unit area: 440 g / m²), 2 Except for Example 1, an all-solid-state secondary battery was fabricated in the same manner.

[0185] (Example 4)

[0186] In addition to changing the foamed metal substrate used as the current collector for both the positive and negative electrodes to a substrate composed of a Ni-Cr alloy with Ni and Cr contents of 65% and 35% by mass, respectively (weight per unit area: 508 g / m²), 2 Except for Example 1, an all-solid-state secondary battery was fabricated in the same manner.

[0187] (Comparative Example 1)

[0188] In addition to changing the foamed metal substrate used as the positive and negative electrodes to a substrate made of pure Ni without Cr (weight per unit area: 330g / m²), 2 Except for Example 1, an all-solid-state secondary battery was fabricated in the same manner.

[0189] (Comparative Example 2)

[0190] In addition to changing the foamed metal substrate used as the positive and negative electrodes to a substrate composed of a Ni-Sn alloy with Ni and Sn contents of 85% and 15% by mass, respectively (weight per unit area: 388 g / m²), 2 Except for Example 1, an all-solid-state secondary battery was fabricated in the same manner.

[0191] For the all-solid-state secondary batteries of the examples and comparative examples, constant current charging was performed at a current value of 4mA until the voltage reached 2.6V, followed by constant voltage charging at 2.6V until the current value reached 0.05mA, and then constant current discharging was performed at a current value of 0.4mA until the voltage reached 1.0V. Then, for each battery, the internal resistance was measured at 1kHz with an applied voltage of 10mV to determine the initial resistance.

[0192] In addition, for each battery whose initial resistance value was measured, it was stored in a constant temperature bath at 115°C for 7 days. After being taken out and cooled to room temperature, constant current charging, constant voltage charging, constant current discharging and internal resistance measurement were performed under the same conditions as when the initial resistance value was measured, and the resistance after storage was calculated.

[0193] Then, for each battery, the rate of increase in resistance is calculated as a percentage of the difference between the storage resistance and the initial resistance divided by the initial resistance.

[0194] In addition, the resistance of the battery after storage was measured by decomposition, and the presence or absence of corrosion in the current collectors of the positive and negative electrodes was confirmed by SEM.

[0195] These results are shown in Table 1.

[0196] [Table 1]

[0197]

[0198] As shown in Table 1, the all-solid-state secondary batteries of Examples 1 to 4, which use Ni-based current collectors for both positive and negative electrodes, exhibited lower resistance rise rates and suppressed resistance increase during high-temperature storage compared to the battery of Comparative Example 1, which uses a Ni-based current collector, and the battery of Comparative Example 2, which uses a Ni-Sn alloy without Cr.

[0199] Furthermore, compared with Example 4, which has a higher Cr content, the all-solid-state secondary batteries of Examples 1 to 3, which have a Cr content of 30% or less in the Ni-Cr alloy, can reduce the resistance of the current collector, thereby reducing the initial resistance of the battery.

[0200] If the batteries of the Examples and Comparative Examples whose resistance after storage was measured were disassembled to confirm the electrodes (positive and negative electrodes), in the batteries of Comparative Examples 1 and 2, a blocky product that is believed to be NiS (nickel sulfide) was confirmed. In contrast, in the batteries of Examples 1 and 2, this product was suppressed, and corrosion of the current collector caused by the reaction with the sulfide-based solid electrolyte contained in the electrodes and the gas from it was well suppressed.

[0201] This invention can also be implemented in ways other than those described above without departing from its spirit. The embodiments disclosed in this application are merely examples, and the invention is not limited to these embodiments. The scope of this invention is interpreted preferentially to the appended claims compared to the description in the foregoing specification, and all modifications within the scope of the claims are included within the scope of the claims.

[0202] Industrial availability

[0203] The all-solid-state battery of the present invention can be applied to the same uses as conventionally known primary and secondary batteries, but because it has a solid electrolyte instead of an organic electrolyte, it exhibits excellent heat resistance and is preferably used in applications exposed to high temperatures. The electrodes for the all-solid-state battery of the present invention can be used to construct the all-solid-state battery of the present invention.

[0204] Symbol Explanation

[0205] 100: All-solid-state battery

[0206] 110: Electrode laminate

[0207] 120: Positive electrode

[0208] 121: Positive electrode mixture layer

[0209] 122: Positive current collector

[0210] 130: Negative electrode

[0211] 131: Negative electrode mixture layer

[0212] 132: Negative current collector

[0213] 140: Solid electrolyte layer

[0214] 150: concave container

[0215] 151: Bottom surface

[0216] 152: Side wall portion

[0217] 153: Support section

[0218] 160: Sealing body

[0219] 170: Connecting terminal section

[0220] 171: Conductive path

[0221] 180: Connecting terminal section

[0222] 181: Conductive path

[0223] 190: Porous metal substrate (conductive connection component)

[0224] 200: Sealing ring

[0225] 210: Elastic conductive component

[0226] 211: Supported part

[0227] 212: Planar part

[0228] 213: Spring section (spring plate)

[0229] 213a: Boundary

[0230] 213b: Front end.

Claims

1. An electrode for an all-solid-state battery, characterized in that, It is an electrode for all-solid-state batteries that includes an active material and a sulfide-based solid electrolyte, as well as a current collector. The current collector is made of an alloy containing Ni and Cr. The alloy contains more than 60% by mass of Ni. The Cr content in the alloy is above 0.1% by mass and below 40% by mass.

2. The electrode for an all-solid-state battery according to claim 1, wherein, The alloy contains more than 70% by mass of Ni.

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

4. The electrode for an all-solid-state battery according to claim 1, wherein, The sulfide-based solid electrolyte contains a sulfide-germanium ore 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. At least a portion of the mixture fills 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 electrode for an all-solid-state battery according to claim 5, wherein, The porous metal substrate has a unit area weight of 600 g / m³. 2 the following.

8. An all-solid-state battery, characterized in that, It has a positive electrode, a negative electrode, and a solid electrolyte layer. At least one of the positive electrode and the negative electrode is an electrode for an all-solid-state battery as described in any one of claims 1 to 7.

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

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