All-solid battery and manufacturing method of all-solid battery

Abstract

To provide an all-solid battery capable of being used in environments with a wide range of temperature changes to thereby contribute to the achievement of the sustainable development goal "9 Let's build a foundation for industry and innovation".SOLUTION: An all-solid battery 1 includes: a battery molded body 20 that has a positive electrode 201, a negative electrode 202, and a solid electrolyte layer 203; a positive power supply plate 30 that is connected to the positive electrode 201 of the battery molded body 20; a negative power supply plate 40 that is connected to the negative electrode 202 of the battery molded body 20; a cylindrical battery can 10 with a bottom that stores cell assembly 21; and a can lid portion 50 that seals the opening at one end of the battery can 10. The lid portion 50 has a conductive electrode terminal 52, and an insulating portion 53 provided around the electrode terminal 52. The battery molded body 20 and the insulating portion 53 are arranged along an axis X1 that intersects with the bottom surface 101 of the battery can 10. The compression direction of the battery molded body 20 and the insulating portion 53 is along the axis X1.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to all-solid-state batteries and methods for manufacturing all-solid-state batteries.

Background Art

[0002] Conventionally, lithium secondary batteries, particularly lithium-ion secondary batteries, have been used in portable electronic devices such as mobile phones or notebook computers, and in electric vehicles and the like. Lithium-ion batteries contain an organic solvent, which is a combustible substance, as a non-aqueous electrolyte. With the development of the above-described devices and electric vehicles, etc., lithium-ion secondary batteries have increased in energy density, and the amount of the organic solvent, which is a combustible substance, has a tendency to increase. As a result, even higher reliability is required for lithium-ion secondary batteries.

[0003] Under such circumstances, all-solid-state lithium secondary batteries (all-solid-state secondary batteries) that do not use an organic solvent have attracted attention. An all-solid-state secondary battery uses a molded body of a solid electrolyte that does not use an organic solvent instead of a conventional organic solvent-based electrolyte. In an all-solid-state secondary battery, a laminate in which a positive electrode layer, a negative electrode layer, and a solid electrolyte layer are laminated is used as a configuration.

[0004] Patent Document 1 discloses a battery in which a laminate is housed in a space formed by a housing and a lid.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The laminate is formed by compressing a solid (powder) material. However, in a high-temperature environment, its strength decreases due to expansion, and in a low-temperature environment, its strength decreases due to contraction, and there is a risk of damage when an impact or the like is applied. On the other hand, all-solid-state batteries that can be used in both high-temperature and low-temperature environments are required.

Means for Solving the Problems

[0007] Among the embodiments disclosed in the present application, the outline of typical ones will be briefly described as follows.

[0008] The all-solid-state battery according to one embodiment includes a cell assembly having a battery molded body having a positive electrode, a negative electrode, and a solid electrolyte layer interposed between the positive electrode and the negative electrode, a positive electrode power supply plate connected to the positive electrode of the battery molded body, and a negative electrode power supply plate connected to the negative electrode of the battery molded body, a bottomed cylindrical battery can that houses the cell assembly, and a can lid portion that seals an opening at one end of the battery can. The can lid portion has a conductive electrode terminal electrically connected to the positive electrode power supply plate or the negative electrode power supply plate, and an insulating portion provided around the electrode terminal. The battery molded body and the insulating portion are arranged along an axial direction intersecting the bottom surface of the battery can. The compression direction of the battery molded body and the insulating portion is along the axial direction.

[0009] The manufacturing method of an all-solid-state battery according to one embodiment includes compressing a positive electrode mixture, a negative electrode mixture, and a solid electrolyte in a first compression direction to form a laminate in which a positive electrode, a negative electrode, and a solid electrolyte layer interposed between the positive electrode and the negative electrode are laminated. A first step of manufacturing a positive electrode tab connected to the positive electrode and a negative electrode tab connected to the negative electrode, attaching the positive electrode tab to the positive electrode of the laminate, and attaching the negative electrode tab to the negative electrode to manufacture a battery formed body; A second step of manufacturing a cell assembly by attaching a positive electrode power supply plate and a negative electrode power supply plate to the positive electrode tab and the negative electrode tab attached to the battery formed body; A third step of accommodating the cell assembly along the first compression direction in an axial direction intersecting the bottom surface of a bottomed cylindrical battery can; A fourth step of compressing an insulating material in a second compression direction to form an insulating portion, and integrally forming a can lid portion having the insulating portion and an electrode terminal which is a conductive material; And a fifth step of attaching the can lid portion to one end of the battery can along the axial direction with the second compression direction.

Effects of the Invention

[0010] According to one embodiment, an all-solid-state battery that can be used even in a high-temperature environment or a low-temperature environment can be provided.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same components are generally denoted by the same reference numerals, and repeated explanations are omitted. In the drawings, the representation of the components may not represent the actual position, size, shape, and range, etc. for the purpose of facilitating the understanding of the invention.

[0013] <Embodiment> With reference to the drawings below, a all-solid-state battery according to an embodiment of the present disclosure will be described. FIG. 1 is an external perspective view of the all-solid-state battery 1 of the embodiment. FIG. 2 is a cross-sectional view of the all-solid-state battery 1 taken along line A-A of FIG. 1. In the following description of the embodiment, the term "all-solid-state battery" is used, but instead of this term, it may be expressed as a laminated solid-state battery, a battery module, or the like.

[0014] The all-solid-state battery 1 includes a battery can 10, a cell assembly 21, a can lid portion 50, and a connection power supply plate 60. The cell assembly 21 is housed inside the battery can 10 and has a battery formed body 20, a holder 22, a positive electrode power supply plate 30, and a negative electrode power supply plate 40. Further, the holder 22 has a support portion.

[0015] <Battery can 10> The battery can 10 has a bottomed cylindrical shape with one end open and the other end closed. Specifically, as shown in the figure, the battery can 10 is a cylindrical can formed in a bottomed cylindrical shape. Inside the battery can 10, a battery formed body 20, a positive electrode power supply plate 30, and a negative electrode power supply plate 40, the details of which will be described later, are housed.

[0016] Note that the battery can 10 is not limited to a cylindrical can, and may be a rectangular tube can or the like with a rectangular cross-section according to the shape of the battery formed body 20 housed inside.

[0017] The battery can 10 has a bottom surface 101 and a side surface 102. The side surface 102 is connected to the bottom surface 101 and extends along a direction intersecting the bottom surface 101, which is the height direction or the horizontal direction depending on the placement, more specifically, along a direction perpendicular to the bottom surface 101.

[0018] Hereinafter, an axis X1 passing through the center of the bottom surface 101 and extending in a direction perpendicular to the bottom surface 101 will be set for the description. Along the axis X1, the bottom surface 101 side of the battery can 10 may be referred to as the lower side, and the tip side (that is, the side away from the bottom surface 101 of the battery can 10) may be referred to as the upper side. Also, the upper side may be referred to as one side of the battery can 10, and the lower side may be referred to as the other side of the battery can 10.

[0019] The battery can 10 is formed of a conductive material, such as a metal material like aluminum, stainless steel, nickel alloy, etc. When the battery can 10 is electrically connected to the negative electrode or the positive electrode described later, the material of the battery can 10 is preferably selected so that corrosion of the battery can 10 or alteration of the material due to alloying with lithium ions does not occur.

[0020] On the outer peripheral wall surface of the side surface 102 of the battery can 10, a plurality of recesses 104 extending upward along the axis X1 from the lower end are formed, for example, by pressing or the like. Thereby, the rigidity of the battery can 10 is increased, and when a strong external force acts on the battery can 10, it is possible to suppress the battery can 10 from being easily crushed or damaged.

[0021] When the recesses 104 are formed, on the inner peripheral wall surface of the side surface 102 of the battery can 10, at the positions where the recesses 104 are formed, protrusions protruding toward the inside of the battery can 10 are formed. When the battery molded body 20 described later is housed inside the battery can 10, this protrusion contacts the side surface of the battery molded body 20. Thereby, it is possible to suppress the battery molded body 20 from vibrating inside the battery can 10.

[0022] Note that the recesses 104 may not be formed on the outer peripheral wall surface of the side surface 102 of the battery can 10. In this case, the battery molded body 20 and the inner peripheral wall surface of the side surface 102 of the battery can 10 are preferably fixed by adhesion. Alternatively, a sealing member or the like formed of a non-conductive material such as a resin material may be disposed in the gap between the battery molded body 20 and the inner peripheral wall surface of the side surface 102 of the battery can 10 to fill the above gap.

[0023] <Cell assembly 21> The cell assembly 21 is housed in the battery can 10 via a buffer sheet 105, which is a soft elastic body having insulation properties such as silicone rubber, between the cell assembly 21 and the bottom surface 101 of the battery can 10. Note that the buffer sheet 105 may not be provided.

[0024] As described above, the cell assembly 21 includes a battery molded body 20, a holder 22, a positive electrode power supply plate 30, and a negative electrode power supply plate 40. As shown in FIG. 2, the cell assembly 21 of the present embodiment includes six battery molded bodies 20 (20a, 20b, 20c, 20d, 20e, 20f). Note that the number of battery molded bodies 20 is not limited to six, and may be more than six or less than six. In the following description, each battery molded body 20 may be referred to as a cell.

[0025] FIG. 3 is an exploded perspective view of the cell assembly 21. In the cell assembly 21, a plurality of battery molded bodies 20 (20a, 20b, 20c, 20d, 20e, 20f) as a plurality of cells and insulating plates 210 (210a, 210b, 210c, 210d, 210e) are laminated along the axis X1. That is, in the cell assembly 21, a plurality of battery molded bodies 20 are arranged along the axis X1. Thereby, a plurality of battery molded bodies 20 can be accommodated in the battery can 10 having a cylindrical shape, and enlargement of the all-solid-state battery 1 can be suppressed.

[0026] The plurality of laminated battery molded bodies 20 are held by the holder 22 from below, side surfaces, and above. In addition, a positive electrode tab 206 included in each of the plurality of battery molded bodies 20 is connected to the positive electrode power supply plate 30. A negative electrode tab 207 included in each of the plurality of battery molded bodies 20 is connected to the negative electrode power supply plate 40.

[0027] The side surface of the cell assembly 21 is covered with a non-conductive heat-shrinkable tube 213 made of a polymer polymer such as polyethylene or various elastomers. That is, the plurality of battery molded bodies 20, the holder 22, the positive electrode power supply plate 30, and the negative electrode power supply plate 40 are covered with the heat-shrinkable tube 213. However, among the holders 22, a second holding portion 24, which will be described later and is disposed on the uppermost surface of the cell assembly 21, is not covered with the heat-shrinkable tube 213. In addition, the vicinity of the upper end portion of the positive electrode power supply plate 30 and the vicinity of the upper end portion of the negative electrode power supply plate 40 are not covered with the heat-shrinkable tube 213.

[0028] <Battery Molded Body 20> Each battery formed body 20 is a laminate 211 in which a formed body (layer) of the positive electrode 201, a formed body (layer) of the negative electrode 202, and a solid electrolyte layer 203 are laminated. Specifically, in the battery formed body 20, the solid electrolyte layer 203 interposed between the positive electrode 201 and the negative electrode 202 is laminated. In FIGS. 2 and 3, the case where the battery formed body 20 is formed in a columnar shape is shown. However, the shape of the battery formed body 20 is not limited to a columnar shape, and may be a polygonal columnar shape such as a rectangular column.

[0029] As shown in FIG. 2, a polarity sheet 201a is attached to one surface of the laminate 211, that is, the surface on which the positive electrode 201 is formed. The polarity sheet 201a is formed in a disk shape according to the shape of the columnar laminate 211. When the laminate 211 is prismatic, the polarity sheet 201a is also formed in a polygonal plate shape according to the shape of the laminate 211.

[0030] A positive electrode tab 206 is joined to the polarity sheet 201a by, for example, resistance welding or the like. Also, a polarity sheet 202a is attached to the other surface of the laminate 211, that is, the surface on which the negative electrode 202 is formed. A negative electrode tab 207 is joined to the polarity sheet 202a by, for example, resistance welding or the like. The polarity sheet 202a is also formed in a shape according to the shape of the laminate 211.

[0031] The side surface, a part of the upper surface, and a part of the lower surface of the laminate 211 are covered with a non-conductive heat-shrinkable tube 212 made of a polymer polymer such as polyethylene or various elastomers.

[0032] <Positive electrode 201> The positive electrode 201 is a columnar formed body (layer) compression-molded by pressing (pressing) a positive electrode mixture. The positive electrode 201 is not limited to a columnar layer, and may be a prismatic layer. The positive electrode mixture is not particularly limited as long as it is, for example, a positive electrode active material used in a lithium-ion secondary battery, that is, a material capable of occluding and releasing lithium ions. Specifically, LiM x Mn 2-xSpinel-type lithium manganese composite oxide represented by O4 (where M is at least one element selected from the group consisting of Li, B, Mg, Ca, Sr, Ba, Ti, V, Cr, Fe, Co, Ni, Cu, Al, Sn, Sb, In, Nb, Mo, W, Y, Ru, and Rh, and 0.01 ≦ x ≦ 0.5), Li x Mn (1-y-x) Ni y M z O (2-k) F l (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, 0.8 ≦ x ≦ 1.2, 0 < y < 0.5, 0 ≦ z ≦ 0.5, k + l < 1, -0.1 ≦ k ≦ 0.2, 0 ≦ l ≦ 0.1) Layered compound represented by LiCo 1-x M x O2 (where M is at least one element selected from the group consisting of Al, Mg, Ti, Zr, Fe, Ni, Cu, Zn, Ga, Ge, Nb, Mo, Sn, Sb, and Ba, and 0 ≦ x ≦ 0.5) Lithium cobalt composite oxide represented by LiNi 1-x M x 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, and 0 ≦ x ≦ 0.5) Lithium nickel composite oxide represented by LiM 1-x N x PO4 (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, and Ba, and 0 ≦ x ≦ 0.5) Olivine-type composite oxide represented by Li4Ti5O 12 Lithium titanium composite oxide represented by etc. may be mentioned, and only one of these may be used, or two or more may be used in combination.

[0033] The average particle diameter 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. Note that the positive electrode active material may be primary particles or secondary particles in which the primary particles are aggregated. When a positive electrode active material having an average particle diameter within the above range is used, more interfaces with the solid electrolyte can be obtained, so that the load characteristics of the battery are further improved.

[0034] The positive electrode active material preferably has a reaction inhibition layer on its surface for suppressing the reaction with the solid electrolyte.

[0035] In the molded body of the positive electrode mixture, if the positive electrode active material and the solid electrolyte come into direct contact, the solid electrolyte may be oxidized to form a resistance layer, and the ionic conductivity in the molded body may decrease. By providing a reaction inhibition layer on the surface of the positive electrode active material to prevent direct contact between the positive electrode active material and the solid electrolyte, it is possible to suppress a decrease in ionic conductivity in the molded body due to oxidation of the solid electrolyte.

[0036] The reaction inhibition layer may be composed of a material having ionic conductivity and capable of suppressing the reaction between the positive electrode active material and the solid electrolyte. Examples of materials that can form 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, Nb-containing oxides such as LiNbO3, Li3PO4, Li3BO3, Li4SiO4, Li4GeO4, LiTiO3, LiZrO3, etc. can be mentioned. The reaction inhibition layer may contain only one of these oxides, or may contain two or more of them. Furthermore, a plurality of these oxides may form a composite compound. Among these oxides, it is preferable to use a Nb-containing oxide, and more preferably LiNbO3.

[0037] The reaction inhibition layer is preferably present on the surface in an amount of 0.1 to 1.0 part by mass with respect to 100 parts by mass of the positive electrode active material. Within this range, the reaction between the positive electrode active material and the solid electrolyte can be favorably suppressed.

[0038] Examples of methods for forming a reaction suppression layer on the surface of the positive electrode active material include the sol-gel method, the mechanofusion method, the CVD method, the PVD method, and the like.

[0039] The content of the positive electrode active material in the positive electrode mixture is preferably 60 to 95% by mass.

[0040] Examples of the conductive assistant for the positive electrode 201 include carbon materials such as graphite (natural graphite, artificial graphite), graphene, carbon black, carbon nanofiber, and carbon nanotube. The content of the conductive assistant in the positive electrode mixture is preferably 1 to 10% by mass.

[0041] As the solid electrolyte for the positive electrode 201, one or more of various sulfide-based solid electrolytes, hydride-based solid electrolytes, and oxide-based solid electrolytes described later that can be used for the negative electrode 202 can be used. In order to make the battery characteristics more excellent, it is desirable to contain a sulfide-based solid electrolyte.

[0042] The content of the solid electrolyte in the positive electrode mixture is preferably 4 to 30% by mass.

[0043] The positive electrode mixture may or may not contain a resin binder. Examples of the resin binder include fluororesins such as polyvinylidene fluoride (PVDF). However, since the resin binder acts as a resistance component in the positive electrode mixture, it is desirable that the amount thereof be as small as possible. Therefore, in the positive electrode mixture, it is preferable not to contain a resin binder, or if it is contained, the content thereof is 0.5% by mass or less. The content of the resin binder in the positive electrode mixture is more preferably 0.3% by mass or less, and further preferably 0% by mass (that is, not containing a resin binder).

[0044] When using a current collector for the positive electrode 201, as the current collector, metal foils such as aluminum and stainless steel, punching metal, wire mesh, expanded metal, foamed metal, carbon sheets, etc. can be used.

[0045] The molded body of the positive electrode mixture can be formed, for example, by compressing a positive electrode mixture prepared by mixing a positive electrode active material, a conductive assistant, a solid electrolyte, and further a binder added as required by pressure molding or the like.

[0046] In the case of a positive electrode having a current collector, it can be manufactured by bonding, such as by crimping, the molded body of the positive electrode mixture formed by the method as described above to the current collector.

[0047] The thickness of the molded body of the positive electrode mixture (in the case of the positive electrode 201 having a current collector, the thickness of the molded body of the positive electrode mixture per side of the current collector. The same shall apply hereinafter) is preferably 200 μm or more from the viewpoint of increasing the capacity of the battery. Also, the thickness of the molded body of the positive electrode mixture is usually 2000 μm or less.

[0048] A positive electrode tab 206 is attached to the positive electrode 201. The positive electrode tab 206 is a metal material such as aluminum, for example. The positive electrode tab 206 is joined to the positive electrode power supply plate 30 described later by welding.

[0049] <Negative electrode 202> The negative electrode 202 is a cylindrical molded body (layer) formed by pressing (pressing) a negative electrode mixture. Note that the negative electrode is not limited to a cylindrical layer, and may be a prismatic layer. The negative electrode mixture can be configured using a negative electrode active material used in a lithium-ion secondary battery. The negative electrode active material is not particularly limited as long as it is a material capable of occluding and releasing lithium ions. For example, carbon-based materials capable of occluding and releasing lithium such as graphite, pyrolytic carbons, cokes, glassy carbons, fired products of organic polymer compounds, mesocarbon microbeads (MCMB), and carbon fibers; simple substances of elements capable of forming alloys with lithium such as Si, Sn, Ge, Bi, Sb, and In, or their oxides or alloys; nitrides containing transition metals such as Co, Ni, Mn, Fe, Cr, Ti, and W and lithium; metallic lithium; lithium alloys such as lithium-aluminum alloys; lithium-containing transition metal oxides such as lithium niobium oxide and lithium titanate, etc. Examples of the lithium titanate include those represented by the following general composition formula (1). Li[Li 1 / 3-a M 1 a Ti 5 / 3-b M 2 b O4(1) In the general composition formula (1), M 1 is at least one element selected from the group consisting of Na, Mg, K, Ca, Sr, and Ba, and M 2 is at least one element selected from the group consisting of Al, V, Cr, Fe, Co, Ni, Zn, Ym, Zr, Nb, Mo, Ta, and W, and 0 ≦ a < 1 / 3, 0 ≦ b ≦ 2 / 3.

[0050] That is, in the lithium titanate represented by the general composition formula (1), a part of the Li site may be substituted with the element M 1 . However, in the general composition formula (1), it is preferable that a representing the ratio of the element M 1 is less than 1 / 3. In the lithium titanate represented by the general composition formula (1), since Li may not be substituted with the element M 1 , the element M 1a, which represents the ratio, may be 0.

[0051] In addition, in the lithium titanate represented by the general composition formula (1), element M 2 is a component for enhancing the electronic conductivity of the lithium titanate. When b, which represents the ratio of element M 2 is in the range of 0 ≤ b ≤ 2 / 3, the effect of improving the electronic conductivity can be ensured well.

[0052] As the negative electrode active material, one or more of the above-exemplified materials can be used. For example, when using lithium titanate, a negative electrode active material other than lithium titanate can also be used together with lithium titanate. However, the ratio of the negative electrode active material other than lithium titanate in the total amount of the negative electrode active material is preferably 30% by mass or less.

[0053] The solid electrolyte of the negative electrode 202 is not particularly limited as long as it has lithium ion conductivity. For example, sulfide-based solid electrolytes, hydride-based solid electrolytes, oxide-based solid electrolytes, etc. can be used.

[0054] Examples of the sulfide-based solid electrolyte include Li2S-P2S5, Li2S-SiS2, Li2S-P2S5-GeS2, Li2S-B2S3-based glasses, etc. In recent years, Li 10 GeP2S 12 (LGPS system) and Li6PS5Cl (Ardillodite system) can also be used. Among these, the Ardillodite-based material, which has particularly high lithium ion conductivity and high chemical stability, is preferably used.

[0055] Examples of the hydride-based solid electrolyte include, for example, LiBH4, a solid solution of LIBH4 and the following alkali metal compound (for example, those having 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 solid solution include at least one selected from the group consisting of lithium halides (such as LiI, LiBr, LiF, LiCl), rubidium halides (such as RbI, RbBr, RbiF, RbCl), cesium halides (such as CsI, CsBr, CsF, CsCl), lithium amide, rubidium amide, and cesium amide.

[0056] Examples of the oxide-based solid electrolyte include, for example, Li7La3Zr2O 12 , LiTi(PO4)3, LiGe(PO4)3, LiLaTiO3, and the like.

[0057] As the solid electrolyte, one or more of those exemplified above can be used. Among the solid electrolytes exemplified above, a sulfide-based solid electrolyte is more preferably used because it has high lithium ion conductivity and a function of enhancing the formability of the negative electrode binder.

[0058] As the conductive aid of the negative electrode 202, for example, a carbon material such as carbon black can be used.

[0059] The negative electrode binder may or may not contain a binder. When the negative electrode binder contains a binder, examples of the binder include fluororesins such as polyvinylidene fluoride (PVDF).

[0060] When a current collector is used for the negative electrode 202, examples of the current collector include foils made of copper, nickel, stainless steel, or aluminum, punching metal, net, expanded metal, foamed metal, carbon sheet, and the like.

[0061] The negative electrode 202 can be manufactured by, for example, mixing particles of lithium titanate oxide as an active material, a solid electrolyte, a conductive assistant, etc. without using a solvent to prepare a negative electrode mixture, and molding this into a pellet shape or the like. Further, a molded body of the negative electrode mixture obtained as described above may be bonded to a current collector to form the negative electrode 202.

[0062] Alternatively, the above negative electrode mixture and a solvent may be mixed to prepare a negative electrode mixture-containing composition, which is applied onto a substrate such as a solid electrolyte layer 203 facing the current collector or the negative electrode 202, dried, and then subjected to a pressing process to form a molded body of the negative electrode mixture.

[0063] It is preferable to select a solvent for the negative electrode mixture-containing composition that is difficult to deteriorate the solid electrolyte. In particular, sulfide-based solid electrolytes and hydride-based solid electrolytes undergo chemical reactions due to a small amount of moisture, so it is preferable to use non-polar aprotic solvents typified by hydrocarbon solvents such as hexane, heptane, octane, nonane, decane, decalin, toluene, and xylene. In particular, it is more preferable to use an ultra-dehydrated solvent having a water content of 0.001 mass% (10 ppm) or less. Further, fluorine-based solvents such as "Bartrel (registered trademark)" manufactured by Mitsui DuPont Fluorochemicals, "Zeolora (registered trademark)" manufactured by Nippon Zeon Co., Ltd., and "Novec (registered trademark)" manufactured by Sumitomo 3M Limited, as well as non-aqueous organic solvents such as dichloromethane and diethyl ether, can also be used.

[0064] As the composition of the negative electrode mixture, for example, the content of the negative electrode active material is preferably 50 to 80 mass%, the content of the solid electrolyte is preferably 20 to 50 mass%, and the content of the conductive assistant is preferably 0.1 to 10 mass%. Further, when the negative electrode mixture contains a binder, its content is preferably 0.1 to 10 mass%. Furthermore, the thickness of the molded body of the negative electrode mixture (including both cases where the negative electrode does not have a current collector and where it has a current collector) is preferably 50 to 1000 μm.

[0065] A negative electrode tab 207 is attached to the negative electrode 202. The negative electrode tab 207 is made of a metal material such as copper, for example. The negative electrode tab 207 is joined to a negative electrode power supply plate 40, which will be described later, by welding.

[0066] <Solid electrolyte layer 203> As the solid electrolyte in the solid electrolyte layer 203, one or more of the same types as those previously exemplified as the solid electrolyte of the negative electrode 202 can be used. However, in order to obtain better battery characteristics, it is desirable to contain a sulfide-based solid electrolyte, and it is more desirable to contain a sulfide-based solid electrolyte in all of the positive electrode 201, the negative electrode 202, and the solid electrolyte layer 203.

[0067] The solid electrolyte layer 203 may have a porous body such as a resin non-woven fabric as a support.

[0068] The solid electrolyte layer 203 is a columnar molded body (layer) formed by compressing (pressing) the solid electrolyte by a method such as pressure molding. Note that the solid electrolyte layer is not limited to a columnar layer, and may be a prismatic layer. Further, the solid electrolyte layer may be formed by a method in which a composition for forming the solid electrolyte layer 203 prepared by dispersing the solid electrolyte in a solvent is applied onto a base material, a positive electrode, or a negative electrode and dried, and pressure molding such as pressing is performed as necessary.

[0069] Similar to the solvent used in the negative electrode binder-containing composition, it is desirable to select a solvent that hardly deteriorates the solid electrolyte for the composition for forming the solid electrolyte layer 203. It is preferable to use the various solvents previously exemplified as the solvent for the negative electrode binder-containing composition, and it is particularly preferable to use an ultra-dehydrated solvent having a contained water content of 0.001 mass% (10 ppm) or less. The thickness of the solid electrolyte layer 203 is preferably 10 to 200 μm.

[0070] <Arrangement of battery molded body 20> In the cell assembly 21, six battery molded bodies 20a, 20b, 20c, 20d, 20e, and 20f are arranged (stacked) in this order from below to above along the axis X1. Each battery molded body 20 is arranged such that the negative electrode 202 is on the lower side and the positive electrode 201 is on the upper side. Note that the arrangement is not limited to the one where the negative electrode 202 of the battery molded body 20 faces downward, and it may be arranged such that the positive electrode 201 faces downward. Also, the battery molded bodies 20 may be arranged in parallel, in series, or in a combination of parallel and series. Thereby, it becomes possible to arrange the battery molded bodies 20 according to the required voltage or current and the arrangement space.

[0071] FIG. 4(A) is an external perspective view of one battery molded body 20 (20a, 20b, 20c, 20d, 20e). FIG. 4(B) is an external perspective view of one battery molded body 20 (20f). As described above, the battery molded body 20 is configured based on a laminate 211 compression-molded by pressing. In the following description, the thickness direction of the compression-molded laminate 211, that is, the thickness direction of the battery molded body 20, is referred to as the first direction L1. It can also be said that the plurality of battery molded bodies 20 stacked along the axis X1 are stacked along the first direction L1.

[0072] The positive electrode tab 206 connected to the positive electrode 201 of the battery molded body 20 has a main part 206a and a connection part 206b. The main part 206a is formed in a plate shape extending in a direction intersecting the first direction L1. The main part 206a is joined to the polarity sheet 201a attached to the positive electrode 201 by, for example, resistance welding or the like, and is electrically connected to the positive electrode 201.

[0073] As shown in FIG. 4(A), the connection part 206b provided on the battery molded bodies 20a, 20b, 20c, 20d, 20e is connected to one end of the main part 206a and extends along the first direction L1, which is a direction intersecting the main part 206a. In the present embodiment, the direction intersecting the main part 206a is a direction orthogonal to the main part 206a.

[0074] As shown in FIG. 4(B), in the positive electrode tab 206 provided on the uppermost battery molded body 20f, a connecting portion 206b is formed via a rising portion 206c that extends upward along the first direction L1 from the end of the main portion 206a described above. The connecting portion 206b extends along the first direction L1. As will be described in detail later, after the connecting portion 206b is housed in a holder 22 to be described later, it is bent and extends in a direction intersecting the first direction L1. In the present embodiment, the direction intersecting the first direction L1 in which the connecting portion 206b extends is a direction orthogonal to the first direction L1.

[0075] The connecting portion 206b is joined to the positive electrode power supply plate 30 by resistance welding or the like. Thereby, the positive electrode 201 of the battery molded body 20 and the positive electrode power supply plate 30 are electrically connected.

[0076] The negative electrode tab 207 connected to the negative electrode 202 of the battery molded body 20 has a main portion 207a and a connecting portion 207b. The main portion 207a is formed in a plate shape extending in a direction intersecting the first direction L1. The main portion 207a is joined to the polarity sheet 202a attached to the negative electrode 202 by, for example, resistance welding or the like, and is electrically connected to the negative electrode 202.

[0077] The connecting portion 207b is connected to the end of the main portion 207a and extends along the first direction L1, which is a direction (specifically, an orthogonal direction) intersecting the main portion 207a. The connecting portion 207b extends from the surface of the negative electrode 202 in a direction approaching the positive electrode 201 along the first direction L1.

[0078] As shown in FIGS. 4(A) and 4(B), the connecting portion 207b of the negative electrode tab 207 and the connecting portion 206b of the positive electrode tab 206 are at positions symmetric with respect to the central axis of the battery molded body 20 having a cylindrical shape (that is, positions where the connecting portion 206b and the connecting portion 207b face each other), and the negative electrode tab 207 is attached. The connecting portion 207b is joined to the negative electrode power supply plate 40 by, for example, resistance welding or the like. Thereby, the negative electrode 202 of the battery molded body 20 and the negative electrode power supply plate 40 are electrically connected.

[0079] As shown in FIGS. 2 and 3, an insulating plate 210, which is a soft elastic body such as silicone rubber, is disposed between each battery molded body 20. Specifically, an insulating plate 210a is disposed between the upper surface of the battery molded body 20a and the lower surface of the battery molded body 20b. An insulating plate 210b is disposed between the upper surface of the battery molded body 20b and the lower surface of the battery molded body 20c. An insulating plate 210c is disposed between the upper surface of the battery molded body 20c and the lower surface of the battery molded body 20d. An insulating plate 210d is disposed between the upper surface of the battery molded body 20d and the lower surface of the battery molded body 20e. An insulating plate 210e is disposed between the upper surface of the battery molded body 20e and the lower surface of the battery molded body 20f.

[0080] The insulating plate 210 is formed in a disk shape according to the cylindrical shape of each battery molded body 20. Note that the insulating plate 210 is not limited to being formed in a disk shape, and may be formed in a shape corresponding to the shape of the battery molded body 20. For example, when the battery molded body 20 has a prismatic shape, the insulating plate 210 is formed in a polygonal plate shape.

[0081] By disposing the insulating plate 210, the battery molded bodies 20a, 20b, 20c, 20d, 20e, and 20f can be arranged in an insulated state. Further, the insulating plate 210, which is a soft elastic body, buffers an impact in the direction of the axis X1 on the battery molded bodies 20 laminated along the axis X1. Further, the insulating plate 210, which is a soft elastic body, suppresses the application of load stress to the portions where the positive electrode tabs 206 and the negative electrode tabs 207 of the battery molded bodies 20 laminated along the axis X1 are joined.

[0082] <Holder 22> The holder 22 holds a plurality of battery molded bodies 20 arranged along the axis X1 (first direction L1). The holder 22 is made of a resin material having insulation, bend resistance, and non-water absorption, such as polypropylene. The holder 22 has a first holding portion 23 and a second holding portion 24. The first holding portion 23 holds the lower side and the side surface of the plurality of laminated battery molded bodies 20. The second holding portion 24 holds the upper side of the uppermost battery molded body 20f among the plurality of laminated battery molded bodies 20.

[0083] As shown in FIG. 3, the first holding part 23 has a bottom surface holding part 231 and four side surface holding parts 232. Note that the number of the side surface holding parts 232 is not limited to four, and may be more than four or less than four. The bottom surface holding part 231 is a circular plate shape corresponding to the shape of the columnar battery molded body 20. Note that when the battery molded body 20 has a prismatic shape, the bottom surface holding part 231 is formed in a polygonal plate shape.

[0084] The side surface holding part 232 extends along the axis X1 and is connected to the bottom surface holding part 231 at the lower end. The four side surface holding parts 232 are provided, for example, at intervals of 90 degrees in the circumferential direction of the bottom surface holding part 231. A hook-shaped bent part 232a is formed above the side surface holding part 232.

[0085] FIG. 5(A) is an external perspective view of the first holding part 23 during molding. As shown in FIG. 5(A), each of the four side surface holding parts 232 extends radially outward from the circumference of the bottom surface holding part 231. By bending in the A1 direction shown in FIG. 5(A) with the bent part 232b near the connection portion with the bottom surface holding part 231 of the side surface holding part 232 as a fulcrum, the first holding part 23 has the shape shown in FIG. 3.

[0086] The battery molded body 20 described later is accommodated in the space surrounded by the bottom surface holding part 231 and the side surface holding part 232. When the battery molded body 20 is accommodated, as shown in FIG. 3, the bent part 232a of the side surface holding part 232 is inclined radially outward from the axis X1. Therefore, the upper end of the side surface holding part 232 does not interfere when the battery molded body 20 is accommodated in the first holding part 23, and the workability is improved.

[0087] Further, as shown in FIG. 3, a sheet 233, which is made of, for example, a silicone material, is disposed between the bottom surface holding portion 231 and the battery molded body 20a. The sheet 233 is provided to facilitate rotation of the battery molded body 20 with respect to the holder 22 when manufacturing the cell assembly 21, the details of which will be described later. By rotating the battery molded body 20 on the sheet 233, the respective positive electrode tabs 206 of the battery molded bodies 20 accommodated in the holder 22 are aligned in the direction of the axis X1, and the respective negative electrode tabs 207 are aligned in the direction of the axis X1, facilitating the positioning adjustment operation. Note that the sheet 233 may not be disposed.

[0088] When the battery molded body 20 is accommodated in the first holding portion 23, above the side surface holding portion 232 is bent in the direction A2 shown in FIG. 3 with the lower end portion 232c of the bent portion 232a as a fulcrum. As a result, the contact surface 232d above the lower end portion 232c of the bent portion 232a contacts the upper surface of the uppermost battery molded body 20f. Then, the upper tip portion 232e formed at the upper end portion of the side surface holding portion 232 above the contact surface 232d extends upward along the axis X1. A latch portion protruding outward is formed at the upper tip portion 232e.

[0089] FIG. 5(B) is an external perspective view of the second holding portion 24. The second holding portion 24 has two semi-circular portions 240 and 241 having a semi-circular shape and a rectangular accommodating portion 242. The accommodating portion 242 is provided between the semi-circular portion 240 and the semi-circular portion 241, is connected to the semi-circular portion 240 by one wall surface, and is connected to the semi-circular portion 241 by a wall surface facing the one wall surface. The upper surface of the accommodating portion 242 is lower than the upper surfaces of the semi-circular portions 240 and 241. That is, the accommodating portion 242 forms a recess with respect to the semi-circular portions 240 and 241.

[0090] The upper surface of the accommodating portion 242 accommodates a connecting portion 206b bent in a direction intersecting the axis X1 (that is, the first direction L1) among the positive electrode tabs 206 provided on the uppermost battery molded body 20f. Further, in the accommodating portion 242, a contact point connecting portion 302 of the positive electrode power supply plate 30, which will be described later, is accommodated above the accommodated connecting portion 206b.

[0091] In the semi-circular portions 240 and 241, two accommodation openings 243 are respectively formed at intervals of, for example, 90 degrees along the circumferential direction. The accommodation openings 243 are through holes that penetrate the semi-circular portions 240 and 241 in the vertical direction. The circumferential length of the accommodation opening 243 is substantially equal to the width of the side surface holding portion 232 of the first holding portion 23, and the radial length of the accommodation opening 243 is substantially equal to the thickness of the side surface holding portion 232.

[0092] When the second holding portion 24 is disposed above the battery molded body 20f in the accommodation opening 243, the upper tip portion 232e of the side surface holding portion 232 of the first holding portion 23 is inserted. When the upper tip portion 232e is inserted into the accommodation opening 243, the latch portion formed on the upper tip portion 232e engages with the upper surfaces of the semi-circular portions 240 and 241, and the second holding portion 24 is fixed to the first holding portion 23.

[0093] Mounting recesses 244 are respectively formed between the two accommodation openings 243 of the semi-circular portion 240 and between the two accommodation openings 243 of the semi-circular portion 241. As will be described in detail later, after the cell assembly 21 is accommodated in the battery can 10, an adhesive for adhesively fixing the cell assembly 21 to the battery can 10 is applied to the mounting recesses 244.

[0094] <Positive electrode current collector plate 30> The positive electrode current collector plate 30 is a metal material such as nickel or aluminum that electrically connects the positive electrode 201 of the battery molded body 20 and an electrode terminal provided on the can lid portion 50 described later. The positive electrode current collector plate 30 has a tab connection portion 301 and a contact connection portion 302. The tab connection portion 301 is formed in a plate shape having a long side along the axis X1. The tab connection portion 301 is joined to the positive electrode tabs 206 attached to the battery molded bodies 20a, 20b, 20c, 20d, and 20e by, for example, resistance welding.

[0095] The contact connection part 302 is formed by bending the positive power supply plate 30 and is connected to the upper end of the tab connection part 301. The contact connection part 302 is accommodated in the accommodation part 242 formed on the upper surface of the second holding part 24 of the holder 22. The lower surface of the contact connection part 302 is joined to the positive tab 206 of the battery molded body 20f accommodated in the accommodation part 242 of the second holding part 24 by, for example, resistance welding or the like.

[0096] In addition, the vicinity of the upper end part of the tab connection part 301 of the positive power supply plate 30 and the contact connection part 302 are not covered by the heat shrinkable tube 213 described above. For this reason, a positive insulating seal 215 is attached, for example, by adhesion in the vicinity of the upper end part of the tab connection part 301 of the positive power supply plate 30, that is, in the vicinity of the position connected to the contact connection part 302.

[0097] <Negative power supply plate 40> The negative power supply plate 40 is a member that electrically connects the negative electrode 202 of the battery molded body 20 and the battery can 10. Specifically, the negative power supply plate 40 is a plate-like member having a long side along the axis X1. The negative power supply plate 40 is a metal material such as nickel or copper, for example. The negative power supply plate 40 is joined to the negative tabs 207 attached to the respective negative electrodes 202 of the plurality of battery molded bodies 20 by, for example, resistance welding or the like.

[0098] The upper end part on the upper side of the negative power supply plate 40 protrudes above the upper end of the cell assembly 21. Two upper end parts 401 and 402 are formed at the upper end of the negative power supply plate 40. That is, the upper end parts 401 and 402 are also not covered by the heat shrinkable tube 213. Each of these two upper end parts 401 and 402 is joined to the inner peripheral wall surface of the side surface 102 of the battery can 10 by welding or the like. In addition, the upper end parts 401 and 402 may not be formed on the negative power supply plate 40, and a single upper end part may be formed.

[0099] <Can lid part 50> The can lid portion 50 is attached to the upper end, which is one end of the battery can 10, thereby sealing the opening of the battery can 10. After being press-fitted into the upper end of the battery can 10, the can lid portion 50 is joined to the battery can 10 by, for example, laser welding or the like, thereby sealing the opening of the battery can 10.

[0100] FIG. 6(A) is a perspective view of the upper side of the can lid portion 50, and FIG. 6(B) is a perspective view of the lower side of the can lid portion 50. The can lid portion 50 includes a main body portion 51, an electrode terminal 52, an insulating portion 53, and an insulating sheet 54.

[0101] The main body portion 51 is, for example, made of a metal material and has a disk shape corresponding to the shape of the opening of the battery can 10. As shown in FIG. 6(B), an insulating sheet 54 is provided on the lower surface of the main body portion 51. Note that the lower surface of the main body portion 51 is the surface facing the bottom surface 101 of the battery can 10 when the can lid portion 50 is attached to the battery can 10. Further, a C surface 510 is formed on the outer peripheral edge of the lower surface of the main body portion 51. The C surface 510 functions as a guide when fitting the can lid portion 50 into the opening of the battery can 10. An opening 511 is formed at the center of the can lid portion 50. The opening 511 is a through hole that penetrates the main body portion 51 in the vertical direction.

[0102] The insulating portion 53 is a non-conductive material such as a glass sintered material or a ceramic sintered material. The insulating portion 53 is provided in the opening 511 of the main body portion 51. An opening 531 is formed at the center of the insulating portion 53. The opening 531 is a through hole that penetrates the insulating portion 53 in the vertical direction.

[0103] The electrode terminal 52 is a conductive material and is disposed in the opening 531. The electrode terminal 52 has a cylindrical shape and is formed by a first protruding portion 521 and a second protruding portion 522. The first protruding portion 521 protrudes upward from the upper surface of the main body portion 51. The first protruding portion 521 comes into contact with an electrical contact or the like of a device to which the all-solid-state battery 1 is mounted.

[0104] The second protruding portion 522 protrudes downward from the lower surface of the main body portion 51. That is, when the can lid portion 50 is attached to the battery can 10, the second protruding portion 522 protrudes toward the bottom surface 101 of the battery can 10. The protruding amount of the first protruding portion 521 with respect to the main body portion 51 is larger than the protruding amount of the second protruding portion 522 with respect to the main body portion 51.

[0105] The second protruding portion 522 protrudes downward by 0.1 mm with respect to the insulating sheet 54 provided on the lower surface of the main body portion 51. The insulating sheet 54 is, for example, a resin material and has a thickness of about 0.1 mm. Therefore, the protruding amount of the second protruding portion 522 downward is about 0.2 mm. In other words, the protruding amount of the second protruding portion 522 is about 0.1 mm larger than the thickness of the insulating sheet 54.

[0106] The second protruding portion 522 is electrically connected to the above-described positive electrode power supply plate 30. Specifically, the second protruding portion 522 is joined to a connection power supply plate 60 described later by, for example, resistance welding or the like. When the positive electrode power supply plate 30 is joined to the battery can 10, the negative electrode power supply plate 40 is electrically connected to the second protruding portion 522.

[0107] The main body portion 51, the electrode terminal 52, and the insulating portion 53 are integrally formed. Specifically, when the insulating portion 53 is a glass sintered material, the glass powder that is the material of the insulating portion 53 is formed by press molding or the like as described later. At this time, the insulating portion 53 can be inserted into the opening 511 of the main body portion 51 and is formed in a cylindrical shape to which the electrode terminal 52 can be attached. Then, the main body portion 51, the electrode terminal 52, and the insulating portion 53 are integrally formed by sintering the glass material of the insulating portion 53 in an electric furnace or the like using the glass hermetic method.

[0108] <Connection power supply plate 60> The connection power supply plate 60 is a plate-shaped member made of a conductive material, such as a metal material like stainless steel, aluminum, nickel alloy, etc. Incidentally, an electric wire may be used as the connection power supply plate 60. As shown in FIG. 2, it has a folded shape formed by alternately bending (folding back) a plate-shaped member in opposite directions at a plurality of bending points (three bending points in FIG. 2). One end of the connection power supply plate 60 is joined to the second protruding portion 522 of the electrode terminal 52 provided on the can lid portion 50 by, for example, resistance welding, laser welding, brazing, etc. The other end of the connection power supply plate 60 is joined to the contact connection portion 302 of the positive electrode power supply plate 30 by, for example, resistance welding, laser welding, brazing, etc. Incidentally, when the positive electrode power supply plate 30 is joined to the battery can 10, the other end of the connection power supply plate 60 is joined to the negative electrode power supply plate 40.

[0109] FIG. 7(A) is a perspective view of the lower side of the can lid portion 50 in a state where the connection power supply plate 60 is joined to the second protruding portion 522. As shown in FIG. 7(A), the width D1 of one end of the connection power supply plate 60 is equal to or greater than the diameter D2 of the second protruding portion 522. For this reason, compared with the case where the width D1 is less than the diameter D2, the contact area between the joined connection power supply plate 60 and the second protruding portion 522 can be increased. As a result, the resistance value at the joint between the connection power supply plate 60 and the electrode terminal 52 can be lowered.

[0110] FIG. 7(B) is an enlarged cross-sectional view of the region B surrounded by the two-dot chain line in FIG. 2. As shown in FIG. 7(B), the connection power supply plate 60 is folded back at the bending points P1, P2, and P3. Due to being folded back at the bending points P1, P2, and P3, a first flat portion 601, a second flat portion 602, a third flat portion 603, a fourth flat portion 604, a first curved portion 605, a second curved portion 606, and a third curved portion 607 are formed on the connection power supply plate 60.

[0111] The first flat portion 601, the second flat portion 602, the third flat portion 603, and the fourth flat portion 604 each extend in a direction intersecting (orthogonal to) the axis X1 and are accommodated inside the battery can 10 and the can lid portion 50 in a state of overlapping with a space therebetween in the direction of the axis X1. The first curved portion 605 is a portion connecting the first flat portion 601 and the second flat portion 602 and is formed by bending the connection power supply plate 60 at the bending point P1. The second curved portion 606 is a portion connecting the second flat portion 602 and the third flat portion 603 and is formed by bending the connection power supply plate 60 at the bending point P2. The third curved portion 607 is a portion connecting the third flat portion 603 and the fourth flat portion 604 and is formed by bending the connection power supply plate 60 at the bending point P3.

[0112] A part (for example, one end portion) of the first flat portion 601 is one end of the connection power supply plate 60 and is joined to the electrode terminal 52. A part (for example, one end portion) of the fourth flat portion 604 is the other end of the connection power supply plate 60 and is joined to the positive electrode power supply plate 30. As described above, since the second protruding portion 522 of the electrode terminal 52 protrudes below the insulating sheet 54, it is suppressed that the connection power supply plate 60 contacts the main body portion 51 and causes a short circuit. Further, even when a high impact force is applied to the all-solid-state battery 1, the momentary disconnection between the connection power supply plate 60 and the electrode terminal 52, the momentary disconnection between the positive electrode power supply plate 30 (that is, the battery molded body 20) and the connection power supply plate 60, and the increase in contact resistance due to rubbing of the contact surface are suppressed, and the decrease in the output voltage of the battery and the occurrence of chattering are suppressed.

[0113] <Manufacturing method of all-solid-state battery 1> Referring to the flowchart shown in FIG. 8, a method for manufacturing the all-solid-state battery 1 will be described. In the first step shown in step S1, a battery formed body 20 is manufactured. In this case, for example, a laminate 211 in which a positive electrode 201, a negative electrode 202, and a solid electrolyte layer 203 are laminated is formed by applying pressure using a press or the like. Also, a positive electrode tab 206 is manufactured from a metal material such as aluminum, and a negative electrode tab 207 is manufactured from a metal material such as copper. Then, the positive electrode tab 206 is joined to the polarity sheet 201a provided on the positive electrode 201 of the laminate 211. Also, the negative electrode tab 207 is joined to the polarity sheet 202a provided on the negative electrode 202 of the laminate 211.

[0114] In the second step shown in step S2, a cell assembly 21 is manufactured. In this case, a plurality of battery formed bodies 20 manufactured by joining the positive electrode tab 206 and the negative electrode tab 207 to the laminate 211 are laminated. Then, the positive electrode power supply plate 30 and the negative electrode power supply plate 40 are attached, whereby the cell assembly 21 is manufactured.

[0115] Incidentally, depending on the manufacturing line, the step of joining the positive electrode tab 206 and the negative electrode tab 207 to the laminate 211 performed in the first step of step S1 described above may be performed in the second step of step S2. In this case, in the second step of step S2, after the positive electrode tab 206 and the negative electrode tab 207 are joined to the laminate 211 and the battery formed body 20 is manufactured, the cell assembly 21 is manufactured. Also, the positive electrode 201, the negative electrode 202, and the solid electrolyte layer 203 of the laminate 211 are laminated along the first direction L1 which is the thickness direction, and a plurality of battery formed bodies 20 in the cell assembly 21 are laminated along the first direction L1.

[0116] In the third step shown in step S3, the cell assembly 21 is housed in the battery can 10. At this time, the cell assembly 21 is housed in the battery can 10 so that the first direction L1 in which a plurality of battery formed bodies 20 are laminated is along the axis X1 of the battery can 10.

[0117] In the fourth step shown in step S4, the can lid portion 50 is manufactured. In this case, the can lid portion 50 is manufactured by integrally molding an insulating portion 53 formed by compressing an insulating material, a main body portion 51, and an electrode terminal 52. Note that the fourth step is not limited to being performed after the third step, and may be performed before the first step, before the second step, or before the third step.

[0118] In the fifth step shown in step S5, the can lid portion 50 is attached to one opening on the axis X1 of the battery can 10, and the opening of the battery can 10 is sealed. Thereby, the all-solid-state battery 1 is manufactured. Hereinafter, each step will be described in detail.

[0119] <First Step (Manufacture of Battery Forming Body 20)> In the first step, first, a laminate 211 is formed using a positive electrode mixture, a negative electrode mixture, and a solid electrolyte. Then, a positive electrode tab 206 is attached to the positive electrode 201 of the laminate 211, and a negative electrode tab 207 is attached to the negative electrode 202, whereby the battery forming body 20 is manufactured.

[0120] <Forming of Laminate 211> Figs. 9(A) to 9(C) are diagrams schematically showing the forming process of the laminate 211. The laminate 211 is generated by pressurizing and compressing a solid (powder) material disposed in a mold using a press or the like. Specifically, first, the above-described solid electrolyte is disposed on a lower pressing die 81 in a cylindrical compression press die 80. As shown in Fig. 9(A), an upper pressing die 82 is disposed on the solid electrolyte, and is pressurized and compressed along the first compression direction shown by an arrow A3 in the figure via the upper pressing die 82 by a press or the like. Thereby, a temporarily formed layer 203b of the solid electrolyte layer 203 is generated.

[0121] As shown in FIG. 9(B), a positive electrode mixture constituting the positive electrode 201 is disposed on the provisional molding layer 203b of the solid electrolyte layer 203, and a polar sheet 201a is disposed on the positive electrode mixture. Then, the polar sheet 201a, the positive electrode mixture, and the provisional molding layer 203b are pressure-compressed along the first compression direction A3 via an upper pressing die 82 by a press or the like. As a result, a provisional molding layer 201b of the positive electrode 201 and the polar sheet 201a are formed on the upper part of the provisional molding layer 203b of the solid electrolyte layer 203.

[0122] Thereafter, as shown in FIG. 9(C), the provisional molding layer 203b of the solid electrolyte layer 203, the provisional molding layer 201b of the positive electrode 201, and the polar sheet 201a are turned upside down. In this case, the provisional molding layer 203b of the solid electrolyte layer 203, the provisional molding layer 201b of the positive electrode 201, and the polar sheet 201a may be once taken out from the compression press die 80, turned upside down, and then disposed again in the compression press die 80.

[0123] Then, after being once taken out from the compression press die 80 and turned upside down, a negative electrode mixture 202b constituting the negative electrode 202 is disposed on the provisional molding layer 203b of the solid electrolyte layer 203, that is, on the surface of the provisional molding layer 203b of the solid electrolyte layer 203 that does not face the provisional molding layer 201b of the positive electrode 201. A polar sheet 202a is disposed on the negative electrode mixture 202b. The polar sheet 202a, the negative electrode mixture 202b, the provisional molding layer 203b of the solid electrolyte layer 203, the provisional molding layer 201b of the positive electrode 201, and the polar sheet 201a are pressure-compressed along the first compression direction A3 via a lower pressing die 81 by a press or the like. As a result, the negative electrode mixture 202b, the provisional molding layer 203b of the solid electrolyte layer 203, and the provisional molding layer 201b of the positive electrode 201 are compressed. As a result, a laminate 211 having the solid electrolyte layer 203, the layered negative electrode 202 on one side of the solid electrolyte layer 203, and the layered positive electrode 201 on the other side of the solid electrolyte layer 203 is formed.

[0124] By being compression-pressed along the first compression direction A3, the laminate 211 is formed into a shape having a thickness in a predetermined direction along the first compression direction A3. In the laminate 211, the positive electrode 201, the solid electrolyte layer 203, and the negative electrode 202 are laminated along the predetermined direction. In other words, the lamination direction of the positive electrode 201, the solid electrolyte layer 203, and the negative electrode 202, the first direction L1, and the first compression direction A3 are aligned (coincide).

[0125] FIG. 10(A) is an external perspective view of the formed laminate 211. By being compressed within the cylindrical compression press mold 80, the laminate 211 is formed into a cylindrical shape. Incidentally, when the compression press mold 80 has a rectangular tube shape, the laminate 211 composed of the positive electrode 201, the solid electrolyte layer 203, and the negative electrode 202 becomes a rectangular prism shape. As described above, the laminate 211 has a thickness along the first direction L1.

[0126] FIG. 10(B) is a plan view of the laminate 211 schematically showing the direction in which the positive electrode 201, the solid electrolyte layer 203, and the negative electrode 202 are extended by compression when the laminate 211 is compressed and formed. Specifically, FIG. 10(B) schematically shows the laminate 211 in a plane orthogonal to the first direction L1.

[0127] At the time of forming, since it is compressed in the first compression direction A3, the laminate 211 is extended in the A4 direction along the radial direction from the center of the laminate 211 toward the outside in the radial direction. For this reason, when the formed laminate 211 is placed in a high-temperature environment, the laminate 211 will have strong resistance in the A4 direction against high-temperature expansion.

[0128] FIG. 10(C) is a plan view of the laminate 211 schematically showing the direction of the force remaining in the laminate 211 after the laminate 211 is compressed. Specifically, FIG. 10(C) schematically shows the laminate 211 in a plane orthogonal to the first direction L1.

[0129] In the formed laminate 211, due to the strain applied to the powder material during compression, a force in the A5 direction along the radial direction remains from the outer peripheral side toward the center of the laminate 211. Therefore, when the formed laminate 211 is placed in a low-temperature environment, the laminate 211 will have strong resistance in the A5 direction against low-temperature shrinkage.

[0130] That is, the laminate 211 has strong resistance against high-temperature expansion and low-temperature shrinkage in the direction intersecting the first direction L1. In other words, in the direction intersecting the first direction L1, it is difficult for the laminate 211 to crack, break, bend, etc. due to temperature changes. On the other hand, in the first direction L1, which is the thickness direction of the laminate 211, the resistance against high-temperature expansion and low-temperature shrinkage is weaker compared to the direction intersecting the first direction L1. Therefore, when a force along the first direction L1 acts on the laminate 211 in a high-temperature environment exceeding, for example, 60°C (for example, an environment of about 60°C to 125°C) or a low-temperature environment lower than -20°C (for example, an environment of about -20°C to -50°C), cracks, breaks, bends, etc. are more likely to occur in the laminate 211 compared to the direction intersecting the first direction L1.

[0131] <Manufacture of Battery Formed Body 20> The battery formed body 20 is manufactured by attaching a heat-shrinkable tube 212, a positive electrode tab 206, and a negative electrode tab 207 to the laminate 211 generated as described above. Since the battery formed body 20 is manufactured by attaching the heat-shrinkable tube 212, the positive electrode tab 206, and the negative electrode tab 207 to the laminate 211, it can also be said that the battery formed body 20 is manufactured by being compressed in the first compression direction A3 described above.

[0132] Figures 11(A) to 11(C) are diagrams showing the manufacturing process of the battery formed body 20. The columnar laminate 211 shown in Figure 10(A) is inserted into the cylindrical heat-shrinkable tube 212 shown in Figure 11(A). When the heat-shrinkable tube 212 is heated in this state, the heat-shrinkable tube 212 shrinks. As a result, as shown in Figure 11(B), the side surface, the upper surface, and the peripheral edges of the lower surface of the laminate 211 are covered by the heat-shrinkable tube 212.

[0133] By attaching the heat-shrinkable tube 212, separation of the laminate 211 and the polar sheets 201a and 202a is suppressed. Further, since the heat-shrinkable tube 212 is made of a non-conductive material, when the battery molded body 20 is housed in the battery can 10, it is possible to insulate the battery molded body 20 from the metal battery can 10.

[0134] As shown in FIG. 11(C), a positive electrode tab 206 and a negative electrode tab 207 are joined to the laminate 211 to which the heat-shrinkable tube 212 is attached, for example, by resistance welding or the like. Specifically, the positive electrode tab 206 is joined to the polar sheet 201a provided on one surface of the laminate 211, that is, the surface on which the positive electrode 201 is formed. Further, the negative electrode tab 207 is joined to the polar sheet 202a provided on the other surface of the laminate 211, that is, the surface on which the negative electrode 202 is formed. Thereby, the battery molded bodies 20 shown in FIGS. 4(A) and 4(B) are manufactured.

[0135] Note that FIG. 11(C) shows a case where the battery molded bodies 20a, 20b, 20c, 20d, and 20e shown in FIG. 4(A) are manufactured.

[0136] Further, the heat-shrinkable tube 212 may be attached after the above-described positive electrode tab 206 and negative electrode tab 207 are joined to the polar sheets 201a and 202a, respectively.

[0137] <Second Step (Manufacture of Cell Assembly 21)> Next, with reference to the external perspective views of the cell assembly 21 during manufacture shown in FIGS. 12(A) to 16, the details of the second step will be described. In the second step, a plurality of battery molded bodies 20 manufactured in the first step are laminated in the first direction L1 within the holder 22. Then, a positive electrode power supply plate 30 is joined to each positive electrode tab 206 of the plurality of battery molded bodies 20 held by the holder 22, and a negative electrode power supply plate 40 is joined to each negative electrode tab 207.

[0138] <Lamination of Battery Molded Bodies 20> First, the first holding portion 23 of the holder 22 is deformed into a shape capable of accommodating the battery molded body 20. Specifically, the first holding portion 23 during molding shown in FIG. 5(A) is bent in the A1 direction with the bent portions 232b of the four side holding portions 232 as fulcrums, so as to be deformed into a shape capable of accommodating the battery molded body 20 as shown in FIG. 3.

[0139] A plurality of battery molded bodies 20 are stacked in a stacking direction along the first direction L1 on the bottom holding portion 231 of the first holding portion 23. As described above, an insulating plate 210 is disposed between the plurality of battery molded bodies 20. Further, when the sheet 233 is disposed, the sheet 233 is provided between the lowermost battery molded body 20a and the bottom holding portion 231.

[0140] FIGS. 12(A) and 12(B) are external perspective views of the cell assembly 21 in a state where a plurality of battery molded bodies 20 are stacked on the first holding portion 23. As shown in FIG. 12(A), the battery molded bodies 20 are stacked such that the negative electrode tabs 207 of the respective battery molded bodies 20 are arranged in a row along the stacking direction (first direction L1). Although not shown in FIG. 12(A), the positive electrode tabs 206 are also arranged in a row along the stacking direction.

[0141] When in the state shown in FIG. 12(A), the bent portion 232a above the side holding portion 232 is bent in the A2 direction with the lower end portion 232c as a fulcrum. Thereby, as shown in the external perspective view of FIG. 12(B), the contact surface 232d of the bent portion 232a contacts the upper surface of the uppermost battery molded body 20f. And the upper tip portion 232e formed at the upper end portion of the contact surface 232d extends along the first direction L1.

[0142] When a plurality of battery molded bodies 20 are stacked within the first holding portion 23, the second holding portion 24 is attached to the upper part of the uppermost battery molded body 20f. FIG. 13(A) is an external perspective view of the cell assembly 21 in a state where the second holding portion 24 is attached. As shown in FIG. 13(A), the upper leading end portion 232e of the first holding portion 23 is inserted into the accommodation opening 243 of the second holding portion 24. The second holding portion 24 is fixed to the first holding portion 23 by the latch portion formed on the upper leading end portion 232e meshing with the upper surface of the second holding portion 24 as described above. As a result, the battery molded body 20 is held from above by the second holding portion 24.

[0143] As shown in FIG. 13(A), the positive electrode tab 206 of the uppermost battery molded body 20f protrudes upward from the second holding portion 24. This positive electrode tab 206 is bent in the A4 direction. Thereby, as shown in FIG. 13(B), the connection portion 206b of the positive electrode tab 206 of the battery molded body 20f is accommodated in the accommodation portion 242 which is a concave portion formed on the upper surface of the second holding portion 24.

[0144] Thereafter, the positive electrode power supply plate 30 and the negative electrode power supply plate 40 are joined. FIG. 14(A) is an external perspective view of the cell assembly 21 showing a state where the positive electrode power supply plate 30 is joined. In this case, the tab connection portion 301 of the positive electrode power supply plate 30 is joined to the positive electrode tabs 206 attached to the battery molded bodies 20a, 20b, 20c, 20d, 20e by resistance welding or the like. Also, the lower surface of the contact connection portion 302 of the positive electrode power supply plate 30 is joined to the upper surface of the connection portion 206b of the positive electrode tab 206 provided on the battery molded body 20f by resistance welding or the like.

[0145] FIG. 14(B) is an external perspective view of a cell assembly 21 showing a state in which a negative electrode power supply plate 40 is joined after a positive electrode power supply plate 30 is joined. As shown in the figure, the negative electrode power supply plate 40 is joined to each of the negative electrode tabs 207 attached to the battery molded bodies 20a, 20b, 20c, 20d, 20e, 20f by resistance welding or the like. Thereby, the cell assembly 21 is manufactured. For convenience of explanation, the negative electrode power supply plate 40 is joined after the positive electrode power supply plate 30 is joined, but the positive electrode power supply plate 30 may be joined after the negative electrode power supply plate 40 is joined.

[0146] The side surface of the cell assembly 21 is covered by the above-described non-conductive heat shrinkable tube 213. Specifically, as shown in the external perspective view of FIG. 15, the cell assembly 21 is inserted into the cylindrical heat shrinkable tube 213. When the heat shrinkable tube 213 is heated in this state, the heat shrinkable tube 213 shrinks. Thereby, as shown in the external perspective view of FIG. 16, the side surface of the cell assembly 21 is covered by the heat shrinkable tube 213.

[0147] That is, the plurality of battery molded bodies 20, the holder 22, the positive electrode power supply plate 30, and the negative electrode power supply plate 40 are covered by the heat shrinkable tube 213. However, the second holding portion 24 of the holder 22 disposed on the uppermost surface of the cell assembly 21 is not covered by the heat shrinkable tube 213. That is, the vicinity of the upper end portion of the tab connection portion 301 of the positive electrode power supply plate 30 and the contact connection portion 302, and the vicinity of the upper end portions 401, 402 of the negative electrode power supply plate 40 are not covered by the heat shrinkable tube 213.

[0148] By covering the side surface of the cell assembly 21 with the heat-shrinkable tube 213, the plurality of battery molded bodies 20 constituting the cell assembly 21 can be fixed, so that the battery molded bodies 20 are suppressed from being separated or falling off. Further, the detachment of the positive power supply plate 30 joined to the positive tab 206 or the detachment of the negative power supply plate 40 joined to the negative tab 207 is suppressed. Further, when the cell assembly 21 is accommodated in the battery can 10 by the heat-shrinkable tube 213, the positive power supply plate 30 is suppressed from directly contacting the battery can 10. As a result, the occurrence of a short circuit due to the contact between the positive power supply plate 30 and the battery can 10 is suppressed.

[0149] Further, as shown in FIG. 16, a positive insulation seal 215 is attached, for example, by adhesion near the upper end of the tab connection portion 301 of the positive power supply plate 30, that is, near the position connected to the contact connection portion 302. By attaching the positive insulation seal 215, the occurrence of a short circuit due to the contact between the positive power supply plate 30 of the cell assembly 21 accommodated in the battery can 10 and the battery can 10 is suppressed. If it is possible to cover the vicinity of the upper end of the tab connection portion 301 of the positive power supply plate 30 with the above heat-shrinkable tube 213, the positive insulation seal 215 does not have to be attached.

[0150] <Third step (accommodation of the cell assembly 21 into the battery can 10)> FIG. 17 is a perspective view for explaining the step of accommodating the cell assembly 21 into the battery can 10, and FIG. 18 is a perspective view of the battery can 10 in which the cell assembly 21 is accommodated. As shown in FIG. 17, first, a buffer sheet 105 is accommodated in the battery can 10. Then, the cell assembly 21 with the heat-shrinkable tube 213 and the positive insulation seal 215 attached is moved downward along the axis X1 from above the battery can 10 and inserted into the battery can 10. That is, the cell assembly 21 is disposed on the bottom surface 101 of the battery can 10 via the buffer sheet 105.

[0151] In the cell assembly 21 inserted into the battery can 10, the first direction L1, which is the direction in which a plurality of battery molded bodies 20 are stacked, is in a state along the axis X1. In other words, the plurality of battery molded bodies 20 are stacked along the axis X1 within the battery can 10. Alternatively, it can be said that the first compression direction A3 of the battery formed body 20 (laminated body 211) is along the axis X1.

[0152] A recess 104 is press-formed on the side surface 102 of the battery can 10, so that a protruding portion protruding toward the axis X1 is formed on the inner peripheral wall surface of the battery can 10. The side surface of the cell assembly 21 accommodated in the battery can 10 contacts the above-mentioned protruding portion. Thereby, the cell assembly 21 is suppressed from vibrating inside the battery can 10.

[0153] The upper end portions 401 and 402 of the negative electrode current collector plate 40 shown in FIG. 18 are not covered by the heat shrinkable tube 213. The negative electrode current collector plate 40 is joined to the battery can 10 by welding or the like at the upper end portions 401 and 402. Thereby, the negative electrode 202 and the battery can 10 are electrically connected by the negative electrode current collector plate 40.

[0154] Thereafter, the cell assembly 21 and the inner peripheral wall surface of the side surface 102 of the battery can 10 are fixed with an adhesive. Specifically, an adhesive is applied across the mounting recess 244 formed in the second holding portion 24 of the holder 22 not covered by the heat shrinkable tube 213 and the inner peripheral wall surface of the side surface 102 of the battery can 10. As the adhesive, a UV adhesive, an epoxy resin-based adhesive, a silicone adhesive, or the like can be used.

[0155] Note that the configuration is not limited to the negative electrode current collector plate 40 being joined to the battery can 10. The positive electrode current collector plate 30 may be joined to the battery can 10. In this case, the negative electrode current collector plate 40 can be configured to contact the electrode terminal 52 of the can lid portion 50 described later.

[0156] <Fourth Step (Manufacture of Can Lid Portion 50)> As described above, the can lid portion 50 is integrally formed from a main body portion 51 and electrode terminals 52 made of a conductive material such as metal, and an insulating portion 53 made of an insulating material. When forming the can lid portion 50, first, a powder, which is the material of the insulating portion 53, is formed by press molding or the like. Specifically, it is formed into a cylindrical shape having an outer diameter that can be inserted into the opening 511 of the main body portion 51 and an inner diameter into which the electrode terminals 52 can be inserted.

[0157] FIG. 19(A) is a diagram schematically showing the forming process of the insulating portion 53. The material (insulating material) 53a of the insulating portion 53 is accommodated in the first compression press mold 90. The first compression press mold 90 has a bottomed cylindrical shape having a bottom surface 901. The axis X2 shown in FIG. 19(A) passes through the center of the bottom surface 901 and is orthogonal to the bottom surface 901.

[0158] The inner diameter of the first compression press mold 90 is substantially equal to the diameter of the opening 511 of the main body portion 51. At the center of the bottom surface 901, a cylindrical protrusion 902 is formed having a diameter substantially equal to the diameter of the electrode terminal 52 (FIG. 2) and extending along the axis X2. The insulating material 53a is accommodated in the space 904 between the bottom surface 901, the inner peripheral wall surface 903, and the cylindrical protrusion 902 of the first compression press mold 90.

[0159] The insulating material 53a accommodated in the first compression press mold 90 is pressurized and compressed in the downward second compression direction A6 along the axis X2 by the second compression press mold 91 from above. The second compression press mold 91 has a diameter substantially equal to the inner diameter of the first compression press mold 90, and a recess 910 having a diameter substantially equal to the diameter of the cylindrical protrusion 902 is formed at the center.

[0160] FIG. 19(B) is an external perspective view of the insulating portion 53 formed by pressure compression. By being compressed within the cylindrical first compression press mold 90, the insulating portion 53 is formed into a shape having a thickness in the second direction L2 along the second compression direction A6. Further, since the cylindrical protrusion 902 is formed on the first compression press mold 90, the insulating portion 53 is formed into a cylindrical shape provided with the opening 511. When the first compression press mold 90 has a rectangular cylindrical shape, the insulating portion 53 has a rectangular cylindrical shape.

[0161] FIG. 19(C) is a plan view of the insulating portion 53 schematically showing the direction in which the insulating portion 53 extends when being formed by compression. Specifically, FIG. 19(C) schematically shows the insulating portion 53 in a plane orthogonal to the second direction L2. During forming, the insulating material 53a is compressed in the second compression direction A6 (i.e., the direction along the second direction L2). For this reason, the insulating portion 53 is extended in the A7 direction from the inside of the insulating portion 53 toward the outer peripheral side along the radial direction and in the A8 direction from the inside of the insulating portion 53 toward the inner peripheral side along the radial direction. For this reason, when the formed insulating portion 53 is placed in a high-temperature environment, the insulating portion 53 will have strong resistance to high-temperature expansion in the A7 and A8 directions.

[0162] FIG. 19(D) is a plan view of the insulating portion 53 schematically showing the direction of the force remaining in the formed insulating portion 53. In the formed insulating portion 53, due to the strain applied to the powder material during compression, a force in the A9 direction from the outer peripheral side of the insulating portion 53 toward the inside along the radial direction and a force in the A10 direction from the inner peripheral side toward the inside along the radial direction remain. For this reason, when the formed insulating portion 53 is placed in a low-temperature environment, the insulating portion 53 will have strong resistance to low-temperature contraction in the A9 and A10 directions.

[0163] That is, the insulating portion 53 has strong resistance to high-temperature expansion and low-temperature contraction in the direction intersecting the second direction L2. In other words, in the direction intersecting the second direction L2, it is difficult for the insulating portion 53 to crack, break, bend, etc. due to temperature changes. In contrast, in the second direction L2 which is the thickness direction of the insulating portion 53, compared with the direction intersecting the second direction L2, the resistance to high-temperature expansion and low-temperature contraction is weak. For this reason, when a force along the second direction L2 acts on the insulating portion 53 in a high-temperature environment exceeding, for example, 60° C. (for example, in an environment of about 60° C. to 125° C.) or in a low-temperature environment lower than -20° C. (for example, in an environment of about -20° C. to -50° C.), the insulating portion 53 is more likely to crack, break, bend, etc. compared with the direction intersecting the second direction L2.

[0164] The insulating part 53 formed as described above is inserted into the opening 511 of the main body part 51. The electrode terminal 52 is inserted into the opening 531 of the insulating part 53. Then, by sintering the insulating material 53a of the insulating part 53, the main body part 51, the electrode terminal 52, and the insulating part 53 are integrally formed as shown in FIGS. 6(A) and 6(B), and the can lid part 50 is manufactured.

[0165] The above-described insulating sheet 54 is attached to the lower surface of the main body part 51 of the can lid part 50. Then, the first flat part 601 of the connection power supply plate 60 is joined to the second protruding part 522 of the electrode terminal 52 by resistance welding or the like. As a result, as shown in FIG. 7(B), the can lid part 50 to which the connection power supply plate 60 is attached is formed.

[0166] <Fifth step (attaching the can lid part 50 to the battery can 10)> In the fifth step, the can lid part 50 manufactured in the fourth step is attached to the battery can 10 in which the cell assembly 21 is housed in the third step.

[0167] FIGS. 20(A) and 20(B) are external perspective views for explaining the step of attaching the can lid part 50 to the battery can 10. First, as shown in FIG. 20(A), the connection power supply plate 60 attached to the can lid part 50 and the positive electrode power supply plate 30 housed in the battery can 10 are joined by, for example, resistance welding or the like. Specifically, the first flat part 601 of the connection power supply plate 60 and the contact connection part 302 of the positive electrode power supply plate 30 housed in the housing part 242 of the second holding part 24 of the holder 22 are joined.

[0168] Thereafter, as shown in FIG. 20(B), with the lower surface of the can lid part 50 facing the upper surface of the second holding part 24, the can lid part 50 is moved downward along the axis X1 and press-fitted into the battery can 10. Thereafter, the peripheral edge of the can lid part 50 and the upper end of the battery can 10 are joined along the joint line by, for example, laser welding or the like. As a result, the battery can 10 is hermetically sealed by the can lid part 50. As a result, the all-solid-state battery 1 having the appearance shown in FIG. 1 is manufactured.

[0169] At this time, the can lid portion 50 is attached to the battery can 10 in a state where the second direction L2, which is the thickness direction of the insulating portion 53, is aligned with the axis X1 of the battery can 10. As described above, the cell assembly 21 is housed in the battery can 10 in a state where the first direction L1, which is the thickness direction of the battery molded body 20, is aligned with the axis X1 of the battery can 10. Therefore, when the can lid portion 50 is attached to the battery can 10, the battery molded body 20 and the insulating portion 53 are arranged to be aligned with the axis X1 in a state where the first direction L1 and the second direction L2 are aligned (coincident state). That is, the battery molded body 20 and the insulating portion 53 are arranged with the direction having low resistance to temperature change aligned with the axis X1. Alternatively, it can be said that the first compression direction A3 of the battery molded body 20 and the second compression direction A6 of the insulating portion 53 are along the axis X1.

[0170] In addition, the hermetic sealing by the can lid portion 50 is performed in a vacuum environment. In this case, the pressure difference is preferably 1 atmosphere (0.1 MPa). By performing the hermetic sealing in a vacuum environment, the inside of the battery can 10 becomes a negative pressure under atmospheric pressure. Therefore, the bottom surface 101 of the battery can 10 is recessed inward. By measuring this dent with, for example, a laser displacement meter or the like, it becomes possible to inspect whether the battery can 10 is hermetically sealed or not.

[0171] In addition, as shown in the external perspective view of FIG. 21, a buffer member 99 may be attached to the upper surface of the can lid portion 50 of the all-solid-state battery 1. In this case, the buffer member 99 is preferably attached to the can lid portion 50 with a weakly adhesive double-sided adhesive tape or the like.

[0172] The buffer member 99 is a soft elastic body having insulation properties such as silicone rubber, for example. The buffer member 99 has a cylindrical shape having an outer diameter substantially equal to the diameter of the can lid portion 50 and an inner diameter into which the first protruding portion 521 of the electrode terminal 52 can be inserted. Also, the length of the buffer member 99 along the axis X1 is larger than the length by which the first protruding portion 521 protrudes from the can lid portion 50.

[0173] As a result, when the all-solid-state battery 1 drops or the like, the electrode terminal 52 collides with the floor or the like, and damage to the electrode terminal 52 due to impact is suppressed. Further, contact between the electrode terminal 52 and the battery can 10 on the same plane of a conductive material such as metal and short-circuiting are suppressed.

[0174] According to the above-described embodiment, at least one of the following operational effects can be obtained.

[0175] (1) The all-solid-state battery 1 includes a battery can 10 having a bottomed cylindrical shape that houses a cell assembly 21 having a battery molded body 20 having a positive electrode 201, a negative electrode 202, and a solid electrolyte layer 203 interposed between the positive electrode 201 and the negative electrode 202, a positive electrode power supply plate 30, and a negative electrode power supply plate 40, and a can lid portion 50 that seals an opening at one end of the battery can 10. The can lid portion 50 has a conductive electrode terminal 52 and an insulating portion 53 provided around the electrode terminal 52. The battery molded body 20 and the insulating portion 53 are arranged along the axis X1 of the battery can 10. The first compression direction A3 of the battery molded body 20 and the second compression direction A6 of the insulating portion 53 are along the axis X1. Further, an elastic member may be disposed between the cell assembly 21 and the inner surface of the battery can 10.

[0176] When the battery molded body 20 and the insulating portion 53 are arranged without aligning the directions (the first direction L1 and the second direction L2) with low resistance to forces acting from the outside in a high-temperature environment or a low-temperature environment, it is necessary to consider impacts in the first direction L1 and the second direction L2 respectively. That is, it is necessary to take measures such as providing a buffer member against impacts acting from a plurality of directions inside the all-solid-state battery 1 or on the device side to which the all-solid-state battery 1 is attached. In contrast, in the present embodiment, since the battery molded body 20 and the insulating portion 53 are arranged in a state where the first direction L1 and the second direction L2 are aligned, it is only necessary to take measures against impacts acting from a single direction.

[0177] As a result, it becomes unnecessary to consider impacts acting from multiple directions, and the design and manufacture of the shock-resistant structure of the all-solid-state battery 1 and the shock-resistant structure of the device to which the all-solid-state battery 1 is attached become easier. Consequently, the all-solid-state battery 1 according to the present embodiment can be used in a high-temperature environment and a low-temperature environment, that is, in an environment with a wider temperature range than the temperature range in which existing batteries can be used. In other words, it is possible to provide an all-solid-state battery 1 that can be used in an environment with a wider temperature range than existing batteries.

[0178] (2) The plurality of battery formed bodies 20 are stacked in the battery can 10 along the axis X1. By taking measures against impacts in a single direction, such as providing an insulating plate 210 made of, for example, a soft elastic body along the axis X1, it is possible to suppress damage to the plurality of battery formed bodies 20 included in the cell assembly 21. As a result, it is possible to provide an all-solid-state battery 1 that can be used even in a high-temperature environment and a low-temperature environment, that is, in an environment with a wide temperature range.

[0179] (3) The connection power supply plate 60 that connects the positive electrode power supply plate 30 and the electrode terminal 52 has a folded-back shape folded at one or more bending points. Thereby, when a high impact force is applied to the all-solid-state battery 1, the momentary disconnection between the connection power supply plate 60 and the electrode terminal 52, the momentary disconnection between the positive electrode power supply plate 30 (that is, the battery formed body 20) and the connection power supply plate 60, and the increase in contact resistance due to rubbing of the contact surface are suppressed. As a result, the decrease in the output voltage of the battery and the occurrence of chattering are suppressed.

[0180] (4) The electrode terminal 52 has a second protruding portion 522 that protrudes toward the bottom surface 101 of the battery can 10 more than the insulating portion 53. One end of the connection power supply plate 60 is connected to the second protruding portion 522, and the other end is connected to the positive electrode power supply plate 30. Thereby, it becomes possible to electrically connect the electrode terminal 52 and the positive electrode 201 via the positive electrode power supply plate 30.

[0181] (5) The width D1 of one end of the connection power supply plate 60 is equal to or greater than the diameter D2 of the second protruding portion 522. Thereby, compared with the case where the width D1 is less than the diameter D2, the contact area between the joined connection power supply plate 60 and the second protruding portion 522 can be increased. That is, the resistance value at the joint between the connection power supply plate 60 and the electrode terminal 52 can be reduced. As a result, it becomes possible to supply more power of a larger capacity from the fully charged all-solid-state battery 1. For example, when the all-solid-state battery 1 is mounted on a mobile device such as a mobile phone, the standby time of the mobile device can be extended.

[0182] (6) An insulating sheet 54 is provided on the surface of the can lid portion 50 on the side facing the bottom surface 101 of the battery can 10, and the protruding amount of the second protruding portion 522 is larger than the thickness of the insulating sheet 54. Thereby, it is possible to prevent the connection power supply plate 60 from contacting the main body portion 51 of the can lid portion 50 and causing a short circuit.

[0183] (7) The protruding amount of the second protruding portion 522 is 0.2 mm. By suppressing the protruding amount of the second protruding portion 522 along the axis X1 to be small, a space for accommodating the battery formed body 20 in the battery can 10 can be secured. That is, while suppressing the increase in size of the all-solid-state battery 1, the size of the battery formed body 20 accommodated in the battery can 10 can be increased, and the capacity of the all-solid-state battery 1 can be increased.

[0184] (8) Each of the plurality of battery formed bodies 20 is arranged via an insulating plate 210. Thereby, the plurality of battery formed bodies 20 are arranged in an insulated state, and the impact in the direction of the axis X1 on the battery formed bodies 20 laminated along the axis X1 is buffered by the insulating plate 210 which is a soft elastic body. That is, since the impact from the direction with low resistance to temperature change is alleviated, even when the temperature change is large, the battery formed body 20 can be prevented from being damaged. As a result, it becomes possible to use the all-solid-state battery 1 in an environment with a wide temperature change range. Further, the insulating plate 210 which is a soft elastic body suppresses the application of load stress to the portions where the positive electrode tab 206 and the negative electrode tab 207 of the battery formed bodies 20 laminated along the axis X1 are joined.

[0185] As described above, the embodiments of the present disclosure have been specifically described. However, the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof. Except for essential components, components can be added, deleted, replaced, etc. Unless otherwise particularly limited, each component may be singular or plural.

[0186] The all-solid-state battery 1 is not limited to having a plurality of battery compacts 20, and may have one battery compact 20.

[0187] The can lid portion 50 is not limited to having a main body portion 51 that is a conductive material. For example, the can lid portion 50 may be integrally formed by an electrode terminal 52 and an insulating portion 53. In this case, the outer diameter of the insulating portion 53 is substantially equal to the inner diameter of the upper end portion of the battery can 10. Then, the can lid portion 50 may be attached to the battery can 10 by fixing the outer peripheral edge of the insulating portion 53 and the upper end portion of the battery can 10 by caulking or the like.

[0188] In the technology according to the present embodiment, a plurality of battery compacts, which are cells, and the insulating portions of the can lid portions are arranged on the battery can with their directions of low resistance to temperature change aligned, so that the all-solid-state battery can be used even in an environment with a wide temperature change range. According to the present invention that provides such a technology, it is possible to contribute to "Build the foundation of industry and technological innovation" among the Sustainable Development Goals (SDGs) proposed by the United Nations.

Description of Reference Numerals

[0189] 1 All-solid-state battery, 10 Battery can, 20, 20a, 20b, 20c, 20d, 20e, 20f Battery formed body, 21 Cell assembly, 22 Holder, 23 First holding part, 24 Second holding part, 30 Positive electrode power supply plate, 40 Negative electrode power supply plate, 50 Can lid part, 51 Main body part, 52 Electrode terminal, 53 Insulating part, 53a Insulating material, 54 Insulating sheet, 60 Connection power supply plate, 101 Bottom surface, 201 Positive electrode, 202 Negative electrode, 203 Solid electrolyte layer, 210, 210a, 210b, 210c, 210d, 210e Insulating plate, 211 Laminated body, 521 First protruding part, 522 Second protruding part, A3 First compression direction, A6 Second compression direction, D1 Width, D2 Diameter, X1 Axis

Claims

1. A cell assembly including a battery formed body having a positive electrode, a negative electrode, and a solid electrolyte layer interposed between the positive electrode and the negative electrode, a positive electrode power supply plate connected to the positive electrode of the battery formed body, and a negative electrode power supply plate connected to the negative electrode of the battery formed body, is housed in a bottomed cylindrical battery can, and a can lid portion for sealing an opening at one end of the battery can, wherein the can lid portion has a conductive electrode terminal electrically connected to the positive electrode power supply plate or the negative electrode power supply plate, and an insulating portion provided around the electrode terminal, the battery formed body and the insulating portion are arranged along an axial direction intersecting with the bottom surface of the battery can, and a compression direction of the battery formed body and the insulating portion is along the axial direction, all-solid-state battery.

2. In the all-solid-state battery according to Claim 1, each of a plurality of the battery formed bodies is laminated in the battery can along the axial direction, all-solid-state battery.

3. In the all-solid-state battery according to Claim 2, a connection power supply plate for connecting the positive electrode power supply plate or the negative electrode power supply plate and the electrode terminal is provided, and the connection power supply plate has a folded-back shape folded at one or more bending points, all-solid-state battery.

4. In the all-solid-state battery according to Claim 3, the electrode terminal has a protruding portion protruding toward the bottom surface of the battery can more than the insulating portion, one end of the connection power supply plate is connected to the protruding portion, and the other end is connected to the positive electrode power supply plate or the negative electrode power supply plate, all-solid-state battery.

5. In the all-solid-state battery according to Claim 4, a width of the one end of the connection power supply plate is equal to or larger than a diameter of the protruding portion, all-solid-state battery.

6. In the all-solid-state battery according to Claim 5, an insulating sheet is provided on a surface of the can lid portion on a side facing the bottom surface of the battery can, and a protruding amount of the protruding portion is larger than a thickness of the insulating sheet, all-solid-state battery.

7. In the all-solid-state battery according to Claim 6, the protruding amount of the protruding portion is 0.2 mm, all-solid-state battery.

8. In the all-solid-state battery according to Claim 1, the battery formed body has a positive electrode tab connected to the positive electrode and a negative electrode tab connected to the negative electrode, the positive electrode tab is connected to the positive electrode power supply plate, and the negative electrode tab is connected to the negative electrode power supply plate, all-solid-state battery.

9. In the all-solid-state battery according to Claim 2, each of a plurality of the battery formed bodies is arranged via an insulating plate, all-solid-state battery.

10. Compress the positive electrode mixture, negative electrode mixture, and solid electrolyte in the first compression direction to form a laminate in which a positive electrode, a negative electrode, and a solid electrolyte layer interposed between the positive electrode and the negative electrode are laminated. Manufacture a positive electrode tab connected to the positive electrode and a negative electrode tab connected to the negative electrode. In a first step, attach the positive electrode tab to the positive electrode of the laminate and the negative electrode tab to the negative electrode to manufacture a battery formed body. In a second step, attach a positive electrode power supply plate and a negative electrode power supply plate to the positive electrode tab and the negative electrode tab attached to the battery formed body to manufacture a cell assembly. In a third step, accommodate the cell assembly along the first compression direction in an axial direction intersecting the bottom surface of a bottomed cylindrical battery can. In a fourth step, compress an insulating material in a second compression direction to form an insulating portion, and integrally form a can lid portion having the insulating portion and an electrode terminal which is a conductive material. In a fifth step, attach the can lid portion to one end of the battery can along the axial direction along the second compression direction. A method for manufacturing an all-solid-state battery comprising the steps.

11. In the method for manufacturing an all-solid-state battery according to claim 10, In the second step, each of a plurality of the battery formed bodies is laminated along the axial direction, and a positive electrode power supply plate and a negative electrode power supply plate are attached to the positive electrode tab and the negative electrode tab attached to each of the plurality of the battery formed bodies. A method for manufacturing an all-solid-state battery.

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