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

Abstract

To provide an all-solid-state battery capable of improving impact resistance and a manufacturing method of the all-solid-state battery.SOLUTION: An all-solid-state battery includes: a battery cell; an impact absorbing material attached to the" battery cell so as to cover a part of an electrode body; and an exterior body having a space formed therein and housing, in the space, the battery cell to which the impact absorbing material is attached. Each of a positive electrode tab and a negative electrode tab has a folded shape that is folded back at one bending point or a folded shape that is folded back in opposite directions alternately at multiple bending points.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an all-solid-state battery and a method for manufacturing an all-solid-state battery. [Background technology]

[0002] Development is being actively carried out to put all-solid-state batteries into practical use. For example, the all-solid-state battery disclosed in Patent Document 1 includes an electrode body having a sulfide solid electrolyte, an exterior body that houses the electrode body, and a pressure member that is disposed between the electrode body and the exterior body and is made of a material that expands without generating gas when heated. According to the disclosure of Patent Document 1, even in the case of a sulfide all-solid-state battery, pressure can be obtained by sealing the battery in the exterior body and then heating it, so that the pressure member can be disposed efficiently and productivity can be improved.

[0003] In addition, in the coin-shaped all-solid-state battery disclosed in Patent Document 2, a flexible conductive porous member (carbon sheet) made of a graphite compact is placed between the positive electrode can, the negative electrode can and the electrode body. According to the disclosure in Patent Document 2, the stress applied to the electrodes (mainly the negative electrode) during the assembly of the battery is alleviated, and cracking of the electrodes can be prevented. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-156220 A [Patent Document 2] WO 2020 / 66323 Summary of the Invention [Problem to be solved by the invention]

[0005] All-solid-state batteries are required to have improved impact resistance. Therefore, one object of the present invention is to provide an all-solid-state battery capable of improving impact resistance and a method for manufacturing the all-solid-state battery. [Means for solving the problem]

[0006] In order to solve the above problems, the all-solid-state battery of the present invention comprises: an electrode body including a positive electrode, a negative electrode, and a solid electrolyte interposed between the positive electrode and the negative electrode, the electrode body having a positive electrode side and a negative electrode side; a positive electrode tab attached to the positive electrode side of the electrode body; and a negative electrode tab attached to the negative electrode side of the electrode body; an elastic member attached to the battery cell so as to cover a portion of the electrode body; and an exterior body in which a space is formed and in which the battery cell with the elastic member attached is housed, and each of the positive electrode tab and the negative electrode tab has a folded shape folded back at one bending point or a folded shape folded back in opposite directions alternately at multiple bending points.

[0007] The method for producing an all-solid-state battery of the present invention is a method for producing an all-solid-state battery comprising: an electrode body including a positive electrode, a negative electrode, and a solid electrolyte interposed between the positive electrode and the negative electrode, the electrode body having a positive electrode side and a negative electrode side; a positive electrode tab attached to the positive electrode side of the electrode body; and a negative electrode tab attached to the negative electrode side of the electrode body; an impact absorbing material attached to the battery cell so as to cover a part of the electrode body; and an exterior body including a cylindrical can serving as a negative electrode terminal in which a space is formed and in which the battery cell with the impact absorbing material attached is housed, and a positive electrode terminal or a metal cap functioning as a positive electrode terminal, wherein each of the positive electrode tab and the negative electrode tab has a folded shape folded back at one bending point or a folded shape folded back in opposite directions alternately at a plurality of bending points, the method comprising the steps of: welding or bonding one end of the positive electrode tab to the positive electrode side of the electrode body to which the impact absorbing material is attached; the other end of the positive electrode tab in a pre-bent state to the metal cap that functions as the positive electrode terminal or the positive electrode terminal of the metal cap by welding or brazing; joining one end of the negative electrode tab in a pre-bent state to a bottom surface of the cylindrical can by welding or brazing, and joining the other end of the negative electrode tab to the negative electrode side surface of the electrode body to which the impact absorbing material is attached by welding or brazing; aligning positions so that the positive electrode tab, the electrode body, and the negative electrode tab are disposed between the metal cap and the cylindrical can; and applying force to at least one of the metal cap and the cylindrical can so as to reduce the distance between the metal cap and the cylindrical can, thereby combining the metal cap and the cylindrical can, bending the positive electrode tab in a pre-bent state, and bending the negative electrode tab in a pre-bent state to form the folded shape. Effect of the Invention

[0008] According to the present invention, it is possible to improve impact resistance. Note that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing the appearance of an all-solid-state battery according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view illustrating an example of the configuration of the all-solid-state battery according to the first embodiment of the present invention. [Diagram 3] FIG. 3 is a cross-sectional view of the all-solid-state battery taken along line II in FIG. [Figure 4] FIG. 4 is an exploded perspective view of a battery cell with shock absorbing material. [Figure 5A] FIG. 5A is a perspective view of the battery cell as viewed from the positive electrode side. [Figure 5B] FIG. 5B is a perspective view of the battery cell as viewed from the negative electrode side. [Figure 5C] FIG. 5C is a cross-sectional view of the battery cell taken along line II-II in FIG. 5A. [Figure 6A] FIG. 6A is a diagram for explaining the shape of the positive electrode tab. [Figure 6B] FIG. 6B is a diagram for explaining the shape of the negative electrode tab. [Figure 6C] FIG. 6C is a diagram for explaining another example of the shape of the positive electrode tab and the shape of the negative electrode tab. [Figure 7] FIG. 7 is a perspective view for explaining the impact absorbing material. [Figure 8A] FIG. 8A is a diagram for explaining the effects of the positive electrode tab and the negative electrode tab. [Figure 8B] FIG. 8B is a diagram for explaining the action and effect of the positive electrode tab and the negative electrode tab. [Figure 9A] FIG. 9A is a diagram for explaining a method for manufacturing an all-solid-state battery. [Figure 9B] FIG. 9B is a diagram for explaining a method for manufacturing an all-solid-state battery. [Figure 9C] FIG. 9C is a diagram for explaining a manufacturing method of an all-solid-state battery. [Figure 9D] FIG. 9D is a diagram for explaining a manufacturing method of an all-solid-state battery. [Figure 9E] FIG. 9E is a diagram for explaining a manufacturing method of an all-solid-state battery. [Figure 9F]FIG. 9F is a diagram showing the completed state of the all-solid-state battery. [Figure 10] FIG. 10 is a perspective view of a battery cell with shock absorbing materials of an all-solid-state battery according to a second embodiment of the present invention. [Figure 11] FIG. 11 is an exploded perspective view of a battery cell with shock absorbing materials of an all-solid-state battery according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <<Summary of the Invention>> First, in order to facilitate understanding of the present invention, an outline of the present invention will be described. All-solid-state batteries that do not use electrolytes have the advantages of being safe, capable of operating in a wide range of temperature environments, from low to high temperatures, and having a long life.

[0011] On the other hand, since electrodes, which are one of the components that make up all-solid-state batteries, are made by compressing and molding powder materials, they tend to be brittle against impacts, and so there is a possibility that all-solid-state batteries will have low impact resistance (durability against external impacts). Therefore, there is a demand for improving the impact resistance of all-solid-state batteries. By improving the impact resistance of all-solid-state batteries, it will become possible to use all-solid-state batteries in applications (situations where they are used) that were previously avoided due to concerns about impacts. Therefore, it is possible to expand the range of applications for all-solid-state batteries.

[0012] One example of a method for improving the impact resistance of an all-solid-state battery is to improve the strength of the powder material electrode. Examples of methods for improving the strength of the powder material electrode include hardening the electrode (i.e., protecting it by making it hard) or adding a binder (increasing the amount added) to soften the electrode (i.e., protecting it from cracking due to softness). However, this method may result in a decrease in battery capacity and a decrease in output.

[0013] Another example of a method for improving the impact resistance of an all-solid-state battery is to harden (make hard) the exterior case (such as an aluminum can) to protect it from impact. However, this method has limitations in terms of impact resistance because it cannot absorb the impact applied to the all-solid-state battery. In other words, there is a limit to how much the battery cell (particularly the electrode body) inside the exterior case can be protected from impact.

[0014] Therefore, the inventors of the present application conducted extensive research and found a configuration that can improve the impact resistance of an all-solid-state battery by a method different from the above-mentioned examples. That is, in the present invention, the impact applied to the all-solid-state battery is absorbed by an impact absorbing material, and further, a specific tab structure (shape) is adopted to soften the impact applied to the electrode body of the all-solid-state battery. As a result, in the present invention, the impact resistance of the all-solid-state battery can be improved.

[0015] In addition, the method of supplying power between the battery cell and battery lid (positive terminal) of the coin battery in Patent Document 2, or between the battery cell and cylindrical can (negative terminal), utilizes an elastic conductive material (such as a carbon cushion) that is disposed between the battery cell and the battery lid and supplies power by surface contact caused by interference in the thickness direction.

[0016] In this case, a strong impact can cause problems such as (1) and (2). (1) The contact is momentarily broken within a few hundred μs (microseconds), and the power supply is cut off. (2) The contact surfaces will rub, increasing contact resistance and decreasing the output voltage from the battery.

[0017] To address these problems (1) and (2), a positive electrode tab is used to electrically connect the battery cell and the battery lid (positive electrode terminal), and one end of the battery cell and the positive electrode tab are directly connected (joined by welding, brazing, etc.) and the battery lid (positive electrode terminal) and the other end of the positive electrode tab are directly connected (joined by welding, brazing, etc.). Similarly, a negative electrode tab is used to electrically connect the battery cell and the cylindrical can (negative electrode terminal), and one end of the battery cell and the negative electrode tab are directly connected (joined by welding, brazing, etc.) and the cylindrical can (negative electrode terminal) and the other end of the negative electrode tab are directly connected (joined by welding, brazing, etc.). This suppresses the occurrence of problems (1) and (2), and the battery is also covered with a shock absorbing material.

[0018] Battery cells covered with shock-absorbing material will move when subjected to impact, which can cause direct connections to come loose and become damaged.

[0019] In contrast, in the present invention, the positive electrode tab and the negative electrode tab are provided with a specific structure (shape), which makes it difficult for the directly connected portions to come off and be damaged. In other words, in the present invention, the positive electrode tab and the negative electrode tab are provided with a specific structure (shape), which makes it possible to improve the impact resistance of the directly connected portions (jointed portions) against impact.

[0020] <<Embodiment>> Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In addition, in all the drawings of the embodiments, the same or corresponding parts may be denoted by the same reference numerals.

[0021] <<First embodiment>> <Configuration> An all-solid-state battery according to a first embodiment of the present invention will be described. Fig. 1 is a perspective view showing the appearance of the all-solid-state battery according to the first embodiment. Fig. 2 is an exploded perspective view for explaining a configuration example of the all-solid-state battery according to the first embodiment. Fig. 3 is a cross-sectional view of the all-solid-state battery taken along line II in Fig. 1.

[0022] As shown in FIG. 1, the all-solid-state battery according to the first embodiment has a cylindrical shape. The all-solid-state battery is not limited to a cylindrical shape. For example, the all-solid-state battery may have other shapes such as a rectangular shape. As shown in FIG. 2, the all-solid-state battery includes a metal cap 100, a cylindrical can 200 having an opening, and a battery cell 300 with a shock absorbing material including a battery cell 310 and a shock absorbing material 320 housed in the cylindrical can 200. The all-solid-state battery uses an exterior body composed of the metal cap 100 and the cylindrical can 200 as an exterior body that exteriors the battery cell 310. The cylindrical can 200 may be referred to as a "first exterior part" for convenience. The metal cap 100 may be referred to as a "second exterior part" for convenience.

[0023] As shown in Fig. 3, the metal cap 100 has an opening 101 penetrating in the thickness direction to accommodate a positive electrode terminal 110 and a gasket 120. The positive electrode terminal 110 and the gasket 120 are provided in the opening 101. The positive electrode terminal 110 is provided on the center side of the opening 101. The gasket 120 is provided so as to surround the positive electrode terminal 110 and to seal a gap between the positive electrode terminal 110 and the opening forming surface of the opening 101. The gasket 120 has a function of insulating the metal cap 100 and the positive electrode terminal 110.

[0024] The positive electrode terminal 110 is made of a metal having electrical conductivity. The gasket 120 is made of a ceramic (nonmetallic inorganic solid material) having electrical insulation, a plastic having electrical insulation, or the like. More specifically, the material of the gasket 120 may be, for example, a ceramic such as a glass sintered material, from the viewpoint of improving heat resistance. In this case, the gasket 120 is manufactured using a glass sealing technique. In addition, the material of the gasket 120 may be, for example, polypropylene or nylon, or, in the case where heat resistance is required in relation to the use of the battery, a heat-resistant resin having a melting point exceeding 240°C, such as a fluororesin such as tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), polyphenylene ether (PEE), polysulfone (PSF), polyarylate (PAR), polyethersulfone (PES), polyphenylene sulfide (PPS), or polyetheretherketone (PEEK), may be used.

[0025] The lower surface of the positive electrode terminal 110 is exposed to the inside of the all-solid-state battery from the opening 101, and the upper surface of the positive electrode terminal 110 is exposed to the outside of the all-solid-state battery from the opening 101. A part of the positive electrode tab 312a of the battery cell 310 contacts the lower surface of the positive electrode terminal 110 exposed to the inside of the all-solid-state battery from the opening 101, and the positive electrode terminal 110 and the positive electrode tab 312a are electrically connected.

[0026] (Cylindrical can) The cylindrical can 200 is made of, for example, metal, has a cylindrical shape including a bottom surface and a side surface extending in the height direction from the bottom surface, and has an opening on the surface facing the bottom surface to form a space for accommodating the shock-absorbing battery cell 300. A part of the negative electrode tab 312b of the battery cell 310 comes into contact with the bottom surface of the cylindrical can 200, and the cylindrical can 200 and the negative electrode tab 312b are electrically connected.

[0027] As described above, in the all-solid-state battery, the positive electrode tab 312a of the battery cell 310 and the positive electrode terminal 110 are electrically connected, and the positive electrode terminal 110 exposed from the opening 101 of the metal cap 100 functions as a positive electrode terminal (positive electrode), and the negative electrode tab 312b of the battery cell 310 and the cylindrical can 200 are electrically connected, and the cylindrical can 200 functions as a negative electrode terminal (negative electrode). On the other hand, the battery cell 310 can also be mounted upside down with respect to the direction of the positive electrode and the negative electrode. In this mounting, the positive electrode tab 312b of the battery cell 310 and the cylindrical can 200 are electrically connected, and the cylindrical can 200 functions as a positive electrode terminal (positive electrode), and the negative electrode tab 312a of the battery cell 310 and the negative electrode terminal 110 are electrically connected, and the negative electrode terminal 110 exposed from the opening 101 of the metal cap 100 functions as a negative electrode terminal (negative electrode).

[0028] (Battery cell with shock absorbing material) Fig. 4 is an exploded perspective view of a battery cell 300 with a shock absorbing material. As shown in Fig. 4, the battery cell 300 with a shock absorbing material includes a battery cell 310 and a shock absorbing material 320. The battery cell 300 with a shock absorbing material is a component in which the shock absorbing material 320 is attached to the battery cell 310 (see Fig. 2).

[0029] (Battery cell) Fig. 5A is a perspective view of the battery cell seen from the positive electrode side, Fig. 5B is a perspective view of the battery cell seen from the negative electrode side, and Fig. 5C is a cross-sectional view of the battery cell taken along line II-II in Fig. 5A.

[0030] The battery cell 310 includes an electrode body 311, a positive electrode tab 312a attached to the positive electrode side surface (positive electrode side surface) of the electrode body 311, and a negative electrode tab 312b attached to the negative electrode side surface (negative electrode side surface) of the electrode body 311. In the following, the positive electrode tab 312a and the negative electrode tab 312b are referred to as "power supply tabs 312" when there is no need to particularly distinguish between them. The electrode body 311 has a cylindrical shape including a positive electrode side surface and a negative electrode side surface facing each other, and a side surface between the positive electrode side surface and the negative electrode side surface. The electrode body 311 is composed of a battery molded body. The battery molded body includes a positive electrode side layer 313, a negative electrode side layer 314, and a solid electrolyte layer 315 interposed between the positive electrode side layer 313 and the negative electrode side layer 314. The battery molded body has a laminated structure in which the solid electrolyte layer 315 is interposed between the positive electrode side layer 313 and the negative electrode side layer 314. The electrode body 311 may have a structure in which a battery molded body is covered with an exterior material.

[0031] (Positive electrode side layer) The positive electrode side layer 313 includes a positive electrode layer 316 and a positive electrode current collector layer 317. The positive electrode side layer 313 may be composed of only the positive electrode layer 316, or may include the positive electrode layer 316, the positive electrode current collector layer 317, and other layers having functions other than these layers. The positive electrode side layer 313 may include the positive electrode layer 316 and other layers.

[0032] The positive electrode layer 316 is formed, for example, of a molded body of a positive electrode mixture containing a positive electrode active material, a conductive assistant, a solid electrolyte, and the like. The positive electrode active material is not particularly limited as long as it is a positive electrode active material used in conventionally known lithium ion secondary batteries, that is, an active material capable of absorbing and releasing Li ions. Specific examples of the positive electrode active material include LiM x Mn 2-x LiO4 (wherein 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), x Mn (1-y-x) Ni y M z O (2-k) Fl (However, 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), a layered compound, LiCo 1-x M x O2 (However, 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, 0 ≦ x ≦ 0.5), a lithium cobalt composite oxide, LiNi 1-x M x O2 (However, M is at least one element selected from the group consisting of Al, Mg, Ti, Zr, Fe, Co, Cu, Zn, Ga, Ge, Nb, Mo, Sn, Sb, and Ba, 0 ≦ x ≦ 0.5), a lithium nickel composite oxide, LiM 1-x N x PO4 (However, 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, 0 ≦ x ≦ 0.5), an olivine-type composite oxide, Li4Ti5O 12 Examples include a lithium titanium composite oxide represented by, etc. 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 the load characteristics of the battery are further improved.

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

[0035] If the positive electrode active material and the solid electrolyte come into direct contact with each other in the positive electrode mixture compact, the solid electrolyte may oxidize to form a resistance layer, which may reduce the ionic conductivity in the compact. By providing a reaction suppression layer that suppresses the reaction with the solid electrolyte on the surface of the positive electrode active material and preventing direct contact between the positive electrode active material and the solid electrolyte, it is possible to suppress the reduction in the ionic conductivity in the compact due to the oxidation of the solid electrolyte.

[0036] The reaction suppression layer may be made of a material that has ion conductivity and can suppress the reaction between the positive electrode active material and the solid electrolyte. Examples of materials that can form the reaction suppression layer include oxides containing Li and at least one element selected from the group consisting of Nb, P, B, Si, Ge, Ti, and Zr, more specifically, Nb-containing oxides such as LiNbO3, Li3PO4, Li3BO3, Li4SiO4, Li4GeO4, LiTiO3, LiZrO3, and the like. The reaction suppression layer may contain only one of these oxides, or may contain two or more of them, and further, a plurality of these oxides may form a composite compound. Among these oxides, it is preferable to use an Nb-containing oxide, and it is more preferable to use LiNbO3.

[0037] The reaction suppression layer is preferably present on the surface in an amount of 0.1 to 1.0 parts by mass per 100 parts by mass of the positive electrode active material. This range allows the reaction between the positive electrode active material and the solid electrolyte to be effectively suppressed. Methods for forming the reaction suppression layer on the surface of the positive electrode active material include the sol-gel method, the mechanofusion method, the CVD method, and the PVD method.

[0038] The content of the positive electrode active material in the positive electrode mixture is preferably 60 to 95 mass %.

[0039] Examples of the conductive assistant for the positive electrode include carbon materials such as graphite (natural graphite, artificial graphite), graphene, carbon black, carbon nanofiber, carbon nanotube, etc. The content of the conductive assistant in the positive electrode mixture is preferably 1 to 10 mass %.

[0040] The solid electrolyte to be contained in the positive electrode active material is not particularly limited as long as it has lithium ion conductivity. For example, sulfide-based solid electrolytes, hydride-based solid electrolytes, halide-based solid electrolytes, oxide-based solid electrolytes, etc. can be used.

[0041] Examples of sulfide-based solid electrolytes include particles such as Li2S-P2S5, Li2S-SiS2, Li2S-P2S5-GeS2, and Li2S-B2S3-based glasses. In recent years, thio-LISICON type materials [Li 10 GeP2S 12 、Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 and so on, Li 12-12a-b+c+6d-e M 1 3+a-b-c-d M 2 b M 3 c M 4 d M 5 12-e X e (where M 1 is Si, Ge or Sn, M 2 is P or V, M 3 is Al, Ga, Y or Sb, M 4 is Zn, Ca, or Ba, M 5 is either S or S and O, X is F, Cl, Br or I, 0≦a<3, 0≦b+c+d≦3, 0≦e≦3), or argyrodite type materials [such as Li6PS5Cl, Li 7-f+g PS 6-x Cl x+y (where 0.05≦f≦0.9, -3.0f+1.8≦g≦-3.0f+5.7), Li 7-h PS 6-h Cl i Br j (where h=i+j, 0<h≦1.8, 0.1≦i / j≦10.0), etc.] can also be used.

[0042] Examples of the hydride-based solid electrolyte include 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, RbF, RbCl), cesium halides (such as CsI, CsBr, CsF, CsCl), lithium amide, rubidium amide, and cesium amide.

[0043] Examples of the halide-based solid electrolyte include monoclinic LiAlCl4, defective spinel-type or layered LiInBr4, monoclinic Li 6-3m Y m X6 (where 0 < m < 2 and X = Cl or Br), and the like. In addition, for example, known ones described in International Publication No. 2020 / 070958 and International Publication No. 2020 / 070955 can also be used.

[0044] Examples of the oxide-based solid electrolyte include garnet-type Li7La3Zr2O 12 , NASICON-type Li 1+O Al 1+O Ti 2-O (PO4)3, Li 1+p Al 1+p Ge 2-p (PO4)3, perovskite-type Li 3q La 2 / 3-q TiO3, and the like.

[0045] Among these solid electrolytes, sulfide-based solid electrolytes are preferred because of their high lithium ion conductivity. Sulfide-based solid electrolytes containing Li and P are more preferred. In particular, argyrodite-type sulfide-based solid electrolytes having high lithium ion conductivity and high chemical stability are even more preferred.

[0046] From the viewpoint of reducing grain boundary resistance, the average particle size of the solid electrolyte is preferably 0.1 μm or more, and more preferably 0.2 μm or more, while from the viewpoint of forming a sufficient contact interface between the active material and the solid electrolyte, the average particle size is preferably 10 μm or less, and more preferably 5 μm or less.

[0047] The content of the solid electrolyte in the positive electrode mixture is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, when the content of the positive electrode active material is 100 parts by mass, from the viewpoint of further increasing the ion conductivity in the positive electrode and further improving the output characteristics of the battery. However, if the amount of the solid electrolyte in the positive electrode mixture is too large, the amount of other components may be reduced, and the effects of these components may be reduced. Therefore, the content of the solid electrolyte in the positive electrode mixture is preferably 65 parts by mass or less, more preferably 60 parts by mass or less, when the content of the positive electrode active material is 100 parts by mass.

[0048] Positive electrode current collector layer 317 can be made of a metal foil such as aluminum, nickel, or stainless steel, a punched metal, a net, an expanded metal, a foamed metal, a carbon sheet, or the like.

[0049] The compact of the positive electrode mixture can be formed, for example, by compressing the positive electrode mixture prepared by mixing the positive electrode active material, the conductive assistant, and the solid electrolyte, and further the binder added as necessary, by pressure molding or the like. In the case of a positive electrode having a current collector (i.e., a positive electrode layer and a positive electrode current collector layer), the compact of the positive electrode mixture formed by the above-mentioned method can be manufactured by bonding it to the current collector by pressure bonding or the like. The thickness of the compact of the positive electrode mixture (in the case of a positive electrode having a current collector, the thickness of the compact of the positive electrode mixture per one side of the current collector. The same applies below.) is preferably 200 μm or more from the viewpoint of increasing the capacity of the battery. In addition, the thickness of the compact of the positive electrode mixture is usually 2000 μm or less.

[0050] (Negative electrode side layer) The negative electrode side layer 314 includes a negative electrode layer 318 and a negative electrode current collector layer 319. The negative electrode side layer 314 may be composed of only the negative electrode layer 318, or may include the negative electrode layer 318, the negative electrode current collector layer 319, and other layers having functions other than these layers. The negative electrode side layer 314 may include the negative electrode layer 318 and other layers.

[0051] The negative electrode layer 318 is composed of, for example, a molded body of a negative electrode mixture containing a negative electrode active material, a conductive assistant, a solid electrolyte, and the like.

[0052] As the negative electrode active material, for example, one or a mixture of two or more carbon-based materials capable of absorbing and releasing lithium, such as graphite, pyrolytic carbons, cokes, glassy carbons, fired organic polymer compounds, mesocarbon microbeads (MCMB), and carbon fibers, can be used. In addition, simple substances containing elements such as Si, Sn, Ge, Bi, Sb, and In, compounds that can be charged and discharged at a low voltage close to that of lithium metal, such as compounds containing lithium nitrides or lithium-containing oxides, lithium metal, and lithium / aluminum alloys can also be used as the negative electrode active material. For example, Li4Ti5O 12 , TiO2, NbO 2.5-δ (0≦δ≦0.5), MoO 3-δ (0≦δ≦1), WO 3-δ (0≦δ≦1), metal oxides such as TiNb2O7, and metal sulfides such as WS2 and MoS2, or a mixture of two or more of these, can also be used as the negative electrode active material. The solid electrolyte is not particularly limited as long as it has lithium ion conductivity. For example, similar to the positive electrode layer, a sulfide-based solid electrolyte, a hydride-based solid electrolyte, a halide-based solid electrolyte, an oxide-based solid electrolyte, etc. can be used.

[0053] The negative electrode current collector layer 319 can be made of a metal foil such as aluminum, nickel, or stainless steel, a punched metal, a net, an expanded metal, a foamed metal, a carbon sheet, or the like.

[0054] The negative electrode mixture compact can be formed, for example, by compressing, by pressure molding, a negative electrode mixture prepared by mixing a negative electrode active material, a conductive assistant, a solid electrolyte, and further a binder added as necessary.

[0055] (Solid electrolyte layer) The solid electrolyte layer 315 includes a solid electrolyte. The solid electrolyte may be one or more of the various sulfide-based solid electrolytes, hydride-based solid electrolytes, and oxide-based solid electrolytes exemplified above as those usable in the positive electrode layer. However, in order to improve the battery characteristics, it is preferable to include a sulfide-based solid electrolyte, and it is more preferable to include a sulfide-based solid electrolyte in all of the positive electrode, negative electrode, and solid electrolyte layer. The solid electrolyte layer may have a porous body such as a resin nonwoven fabric as a support. The solid electrolyte layer 315 can be formed by a method of compressing the solid electrolyte by pressure molding, or a method of applying a solid electrolyte layer forming composition prepared by dispersing the solid electrolyte in a solvent onto the substrate, positive electrode, and negative electrode, drying, and performing pressure molding such as pressing as necessary.

[0056] It is preferable to select a solvent that does not deteriorate the solid electrolyte for use in the composition for forming the solid electrolyte layer. In particular, since sulfide-based solid electrolytes and hydride-based solid electrolytes undergo chemical reactions due to a small amount of water, it is preferable to use a non-polar aprotic solvent represented by a hydrocarbon solvent such as hexane, heptane, octane, nonane, decane, decalin, toluene, or xylene. In particular, it is more preferable to use an ultra-dehydrated solvent with a water content of 0.001 mass% (10 ppm) or less. In addition, fluorine-based solvents such as "Vertrel (registered trademark)" manufactured by Mitsui DuPont Fluorochemicals Co., Ltd., "Zeorolla (registered trademark)" manufactured by Nippon Zeon Co., Ltd., and "Novec (registered trademark)" manufactured by Sumitomo 3M Co., Ltd., as well as non-aqueous organic solvents such as dichloromethane and diethyl ether can also be used. The thickness of the solid electrolyte layer is preferably 10 to 300 μm.

[0057] (Power supply tab) The power supply tab 312 is made of a conductive material. The power supply tab 312 is, for example, a plate-shaped body made of a conductive material such as metal. A positive electrode tab 312a attached to the positive electrode side surface of the battery cell 310 functions as a positive electrode terminal of the battery cell 310. A negative electrode tab 312b attached to the negative electrode side surface of the battery cell 310 functions as a negative electrode terminal of the battery cell 310.

[0058] Fig. 6A is a diagram for explaining the shape of the positive electrode tab. Fig. 6B is a diagram for explaining the shape of the negative electrode tab. As shown in Fig. 6A, the positive electrode tab 312a has a folded shape formed by bending (folding) a straight plate-like body in alternate opposite directions at multiple bending points (two bending points in this example).

[0059] Specifically, in the positive electrode tab 312a, for the portion from one end to the bend point P1, at the bend point P1, the portion from the bend point P1 to the bend point P2 is folded back in the direction toward one main surface MS1, and at the bend point P2, the portion from the bend point P2 to the other end is folded back in the direction toward the other main surface MS2 (i.e., the portion is folded back in opposite directions alternately at adjacent bend points P1 and P2).

[0060] Such a positive electrode tab 312a includes a first flat portion 312a1, a first bent portion 312a2, a second flat portion 312a3, a second bent portion 312a4, and a third flat portion 312a5.

[0061] The first flat portion 312a1 and the third flat portion 312a5 have the same or approximately the same length, and the second flat portion 312a3 is longer than the first flat portion 312a1 and the third flat portion 312a5.

[0062] The first bent portion 312a2 is, for example, a substantially semicircular arc shape with the left half of the circle cut out, and the second bent portion 312a4 is a substantially semicircular arc shape with the right half of the circle cut out. The shape of the bent portion is not limited to a substantially circular arc shape. A gap is formed between the first flat portion 312a1 and the second flat portion 312a3, and a gap is formed between the second flat portion 312a3 and the third flat portion 312a5. The adjacent and opposing flat portions forming this gap may be in a state of partial contact depending on the state of use.

[0063] 6B, the negative electrode tab 312b has a shape similar to that of the positive electrode tab 312a. The negative electrode tab 312b has a folded shape formed by bending (folding) a straight plate-like body in alternate opposite directions at multiple bending points (two bending points in this example).

[0064] Specifically, in the negative electrode tab 312b, with respect to the portion from one end to the bending point P11, at the bending point P11, the portion from the bending point P11 to the bending point P12 is folded back in the direction toward one main surface MS1, and at the bending point P12, the portion from the bending point P12 to the other end is folded back in the direction toward the other main surface MS2 (i.e., the portion is folded back in opposite directions alternately at adjacent bending points P11 and P12).

[0065] Such a negative electrode tab 312b includes a first flat portion 312b1, a first bent portion 312b2, a second flat portion 312b3, a second bent portion 312b4, and a third flat portion 312b5.

[0066] The first flat portion 312b1 and the third flat portion 312b5 have approximately the same length, and the second flat portion 312b3 is longer than the first flat portion 312b1 and the third flat portion 312b5.

[0067] The first bent portion 312b2 is, for example, a substantially semicircular arc shape with the left half of the circle cut out, and the second bent portion 312b4 is a substantially semicircular arc shape with the right half of the circle cut out. The shape of the bent portion is not limited to a substantially arc shape. A gap is formed between the first flat portion 312b1 and the second flat portion 312b3, and a gap is formed between the second flat portion 312b3 and the third flat portion 312b5. The adjacent and opposing flat portions forming this gap may be in partial contact depending on the state of use.

[0068] By forming a folded shape in which the positive electrode tab 312a and the negative electrode tab 312b are alternately folded in opposite directions at multiple bending points, the flexibility and elasticity of the positive electrode tab 312a and the negative electrode tab 312b are improved, and the positive electrode tab 312a and the negative electrode tab 312b are easily deformed in response to the displacement of the electrode body 311, so that a function of absorbing impacts in the up-down and left-right directions can be imparted. This makes it possible to absorb impacts applied to the electrode body 311 of the battery cell 310 and to mitigate the impact applied to the electrode body 311.

[0069] In addition, a part (e.g., one end) of the first flat portion 312a1 of the positive electrode tab 312a is joined to the positive electrode side surface of the electrode body 311 by welding (laser welding, spot welding, etc.), brazing, etc., and a part (e.g., the other end) of the third flat portion 312a5 of the positive electrode tab 312a is joined to the underside of the positive electrode terminal 110 inside the metal cap 100 (the positive electrode terminal 110 in the area facing the positive electrode side surface of the electrode body 311) by welding (laser welding, spot welding, etc.), brazing, etc., and the surface of the third flat portion 312a5 is in contact with the underside of the positive electrode terminal 110 inside the metal cap 100. Even if a strong impact is applied to the all-solid-state battery, the welded or brazed parts prevent a momentary disconnection between the positive terminal 110 and the positive tab 312a, a momentary disconnection between the electrode body 311 and the positive tab 312a, and the contact surfaces are rubbed to increase contact resistance, resulting in a decrease in output voltage from the battery, and chattering is also unlikely to occur.

[0070] Furthermore, a part (e.g., the other end) of the third flat portion 312b5 of the negative electrode tab 312b is joined to the negative electrode side surface of the electrode body 311 by welding (laser welding, spot welding, etc.), brazing, etc., and a part (e.g., one end) of the first flat portion 312b1 of the negative electrode tab 312b is joined to the inner bottom surface of the cylindrical can 200 (a region facing the negative electrode side surface of the electrode body 311 on the bottom surface) by welding (laser welding, spot welding, etc.), brazing, etc., and the surface of the first flat portion 312b1 is in contact with the inner surface of the cylindrical can 200. Due to the welded or brazed portion, even if a high impact is applied to the all-solid-state battery, it is difficult to cause a momentary interruption between the cylindrical can 200 and the negative electrode tab 312b, a momentary interruption between the electrode body 311 and the negative electrode tab 312b, a friction between the contact surfaces causing an increase in contact resistance, a decrease in the output voltage from the battery, and chattering.

[0071] On the other hand, the battery cell covered with the shock absorbing material 320 moves due to the shock, which may cause the directly connected portion to come off and become damaged. In response to this, the positive electrode tab 312a and the negative electrode tab 312b are folded back in opposite directions at multiple bending points to form a folded shape, which can improve the shock resistance of the welded or brazed portions (directly connected portions) against shock.

[0072] The shapes of the positive electrode tab 312a and the negative electrode tab 312b are not limited to the folded shapes bent (folded) in opposite directions at two bending points as shown in FIG. 6A and FIG. 6B. As shown in FIG. 6C, the shapes of the positive electrode tab 312a and the negative electrode tab 312b may be folded in opposite directions at three bending points. That is, the shapes of the positive electrode tab 312a and the negative electrode tab 312b may be folded in opposite directions at three bending points. In this case, when the positive electrode tab 312a is welded or brazed to the electrode body 311 and the metal cap 100, if the positive electrode tab 312a is divided into one side and the other side at the boundary, the welding or brazing operation can be performed from the same side, which is preferable from the viewpoint of ease of work. Similarly, when welding or brazing the negative electrode tab 312b to the electrode body 311 and the cylindrical can 200, if the negative electrode tab 312b is used as a boundary to separate the negative electrode tab 312b into one side and the other side, the welding or brazing work can be performed from the same side, which is preferable from the standpoint of ease of work.

[0073] The positive electrode tab 312a and the negative electrode tab 312b may have a folded shape folded back at one bending point or a folded shape folded back in opposite directions alternately at four or more bending points. That is, the positive electrode tab 312a and the negative electrode tab 312b may have a folded shape formed by bending (folding back) a straight plate-like body at one bending point, or may have a folded shape formed by bending (folding back) the straight plate-like body at four or more bending points alternately in opposite directions.

[0074] 6A and 6B, these shapes can improve the flexibility and elasticity of the power supply tab 312 to follow the displacement of the electrode body 311, thereby absorbing the impact applied to the electrode body 311 of the battery cell 310 and mitigating the impact applied to the electrode body 311. From the viewpoint of better impact absorption, a folded shape in which the power supply tab 312 is folded back in opposite directions alternately at multiple bending points is more preferable than a folded shape in which the power supply tab 312 is folded back at a single bending point.

[0075] (shock absorbing material) The shock absorbing material 320 is made of a material having shock absorbing properties. Examples of the material having shock absorbing properties include a very soft gel-like material mainly made of silicone, butyl rubber, silicone rubber, and a low-resilience soft material such as a foam cushion. In this embodiment, an elastic member capable of absorbing shocks can also be used as the shock absorbing material 320.

[0076] FIG. 7 is a perspective view for explaining a configuration example of the impact absorbing material. As shown in FIG. 7, the impact absorbing material 320 has a tubular shape (for example, a cylindrical shape) with one end surface and the other end surface open. The impact absorbing material 320 may have a tubular shape with only one end surface open, or may have a rectangular sheet shape. The impact absorbing material 320 has a shape that can be attached to the battery cell 310 so that the electrode body 311 of the battery cell 310 enters the space SP1 surrounded by the inner circumferential surface, and the electrode body 320 covers the peripheral end of the positive electrode side surface, the peripheral end of the negative electrode side surface, and the side surface of the electrode body 311, avoiding the contact portion with the power supply tab 312 of the electrode body 311 (the contact portion with the power supply tab 312 on the positive electrode side surface and the negative electrode side surface).

[0077] More specifically, for example, the inner peripheral surface of the cylindrical impact absorbing material 320 has a concave groove shape. The groove shape includes a bottom 320a of the groove, a first wall 320b extending inward from the bottom 320a, and a second wall 320c facing the first wall 320b and extending inward from the bottom 320a approximately parallel to the first wall 320b. The distance between the first wall 320b and the second wall 320c is slightly longer than the thickness of the electrode body 311 of the battery cell 310.

[0078] The battery cell 310 is arranged in the space SP1 in a state in which the peripheral edge of the positive electrode side and the peripheral edge and side of the negative electrode side of the electrode body 311 of the battery cell 310 fit between the first wall portion 320b and the second wall portion 320c of the impact absorbing material 320, the side of the electrode body 311 faces the bottom 320a of the groove with a small gap between them, the opposing first wall portion 320b and second wall portion 320c of the impact absorbing material 320 contact the peripheral edge of the positive electrode side and the lower peripheral edge of the electrode body 311, and the peripheral edge of the positive electrode side and the peripheral edge of the negative electrode side of the electrode body 311 are sandwiched between the first wall portion 320b and the second wall portion 320c (see Figures 2 and 3). The contact portions between the positive electrode tab 312a and the negative electrode tab 312b of the electrode body 311 of the battery cell 310 arranged in the space SP1 are not covered with the impact absorbing material 320 (see FIGS. 2 and 3).

[0079] In this state, when the shock absorbing material 320 is attached to the battery cell 310, the shock absorbing material 320 covers the peripheral end of the positive electrode side surface of the electrode body 311, the peripheral end of the negative electrode side surface, and the side surface of the electrode body 311 with the first wall portion 320b, the second wall portion 320c, and the bottom portion 320a of the shock absorbing material 320, while avoiding the contact portion with the power supply tab 312 of the electrode body 311. As a result, the shock absorbing material 320 can absorb the shock applied to the electrode body 311 of the battery cell 310 and reduce the shock applied to the electrode body 311. Furthermore, when the shock absorbing material 320 is attached to the battery cell 310, the shock absorbing material 320 covers a part of the electrode body 311 while avoiding the contact portion with the power supply tab 312 of the electrode body 311, so that the shock resistance can be improved without interfering with the electrical connection between the electrode body 311 and the power supply tab 312.

[0080] The effects of the all-solid-state battery according to the first embodiment will be described in detail below. As described above, in the all-solid-state battery according to the first embodiment, the shock absorbing material 320 is attached so as to cover the peripheral end of the positive electrode side surface and the peripheral end and side surface of the negative electrode side surface of the electrode body 311 of the battery cell 310. The shock absorbing material 320 is made of a material having shock absorbing properties. Therefore, the shock applied to the electrode body 311 of the battery cell 310 from the outside of the all-solid-state battery is absorbed by the shock absorbing material 320, so that the shock resistance of the all-solid-state battery can be improved.

[0081] Furthermore, the all-solid-state battery has a shape in which the positive electrode tab 312a and the negative electrode tab 312b are alternately folded in opposite directions at multiple bending points, which also improves the shock absorption of the all-solid-state battery, thereby improving the shock resistance of the all-solid-state battery.

[0082] Furthermore, a portion of the positive electrode tab 312a is welded or brazed to the positive electrode terminal 110 and is in face-to-face contact, so that the conductive state can be maintained even when a strong impact is applied. Further, a portion of the negative electrode tab 312b is welded or brazed to the bottom surface of the cylindrical can 200 and is in face-to-face contact, so that the conductive state can be maintained even when a strong impact is applied.

[0083] Furthermore, one end of the positive electrode tab 312a is welded or brazed to the positive electrode terminal 110, and the other end is welded or brazed to the positive electrode side surface of the electrode body 311. As a result, even if a high impact is applied to the all-solid-state battery, there is little chance of a momentary disconnection between the positive electrode terminal 110 and the positive electrode tab 312a, or between the electrode body 311 and the positive electrode tab 312a, or the contact surfaces are rubbed, increasing contact resistance, causing a drop in the output voltage from the battery, and chattering.

[0084] Furthermore, one end of the negative electrode tab 312b is welded or brazed to the bottom surface of the cylindrical can 200, and the other end is welded or brazed to the negative electrode side surface of the electrode body 311. As a result, even if a high impact is applied to the all-solid-state battery, there is less chance of a momentary disconnection between the cylindrical can 200 and the negative electrode tab 312b, or between the electrode body 311 and the negative electrode tab 312b, and the contact surfaces are rubbed, increasing contact resistance, causing a decrease in the output voltage from the battery, and chattering.

[0085] On the other hand, the battery cell covered with the shock absorbing material 320 moves due to the shock, which may cause the directly connected portion to come off and become damaged. In response to this, the positive electrode tab 312a and the negative electrode tab 312b are folded back in opposite directions at multiple bending points to form a folded shape, which can improve the shock resistance of the welded or brazed portions (directly connected portions) against shock.

[0086] The effect of the positive electrode tab 312a and the negative electrode tab 312b will be described with reference to Figures 8A and 8B. As shown in Figure 8A, when the electrode body 311 of the battery cell 310 moves in the left-right direction (arrow a1) due to an impact on the all-solid-state battery, the folded shapes of the positive electrode tab 312a and the negative electrode tab 312b deform in accordance with the movement displacement (distortion), thereby receiving and absorbing the impact applied to the electrode body 311, thereby mitigating the impact applied to the electrode body 311.

[0087] At this time, the third flat portion 312a5 of the positive electrode tab 312a remains in contact with the positive electrode terminal 110, and the first flat portion 312b1 of the negative electrode tab 312b remains in contact with the cylindrical can 200, so that electrical continuity is maintained between the cylindrical can 200 and the negative electrode tab 312b.

[0088] The surface of the third flat portion 312a5 of the positive electrode tab 312a and the surface of the positive electrode terminal 110 are partially welded or brazed to be in close contact with each other, so that the conductive state between the positive electrode terminal 110 and the positive electrode tab 312a can be maintained even against a high impact. Similarly, the surface of the first flat portion 312b1 of the negative electrode tab 312b and the surface of the cylindrical can 200 are partially welded or brazed to be in close contact with each other, so that the conductive state between the cylindrical can 200 and the negative electrode tab 312b can be maintained even against a high impact in the left-right direction.

[0089] Furthermore, even if a high impact is applied to the all-solid-state battery in the left-right direction, the "positive electrode tab 312a and the positive electrode terminal 110, and the welded or brazed portion of the positive electrode tab 312a and the electrode body 311" and the "negative electrode tab 312b and the cylindrical can 200, and the welded or brazed portion of the negative electrode tab 312b and the electrode body 311" prevent a momentary interruption between the positive electrode terminal 110 and the positive electrode tab 312a, a momentary interruption between the electrode body 311 and the positive electrode tab 312a, a momentary interruption between the cylindrical can 200 and the negative electrode tab 312b, a momentary interruption between the electrode body 311 and the negative electrode tab 312b, a friction between the contact surfaces increases the contact resistance, and the output voltage from the battery decreases and chattering does not occur. On the other hand, the battery cell 310 covered with the shock absorbing material 320 moves in the left-right direction due to the impact, so that the directly connected parts may come off and be damaged. In contrast, the folded shapes of the positive electrode tab 312a and the negative electrode tab 312b deform in response to movement and displacement (distortion), thereby improving the impact resistance of the welded or brazed portions (directly connected portions) against impact.

[0090] As shown in FIG. 8B, when the electrode body 311 moves in the up-down direction (arrow b1) due to an impact on the all-solid-state battery, the folded shapes of the positive electrode tab 312a and the negative electrode tab 312b deform in accordance with the moving displacement (distortion) to receive and absorb the impact applied to the electrode body 311, thereby mitigating the impact applied to the electrode body 311.

[0091] At this time, the third flat portion 312a5 of the positive electrode tab 312a remains in contact with the positive electrode terminal 110, and the first flat portion 312b1 of the negative electrode tab 312b remains in contact with the cylindrical can 200, so that electrical continuity is maintained between the cylindrical can 200 and the negative electrode tab 312b.

[0092] The surface of the third flat portion 312a5 of the positive electrode tab 312a and the surface of the positive electrode terminal 110 are partially welded or brazed to be in close contact with each other, so that the conductive state between the positive electrode terminal 110 and the positive electrode tab 312a can be maintained even against a high impact. Similarly, the surface of the first flat portion 312b1 of the negative electrode tab 312b and the surface of the cylindrical can 200 are partially welded or brazed to be in close contact with each other, so that the conductive state between the cylindrical can 200 and the negative electrode tab 312b can be maintained even against a high impact in the vertical direction.

[0093] Furthermore, even if a high impact is applied to the all-solid-state battery in the vertical direction, the "positive electrode tab 312a and the positive electrode terminal 110, and the welded or brazed portion of the positive electrode tab 312a and the electrode body 311" and the "negative electrode tab 312b and the cylindrical can 200, and the welded or brazed portion of the negative electrode tab 312b and the electrode body 311" prevent a momentary interruption between the positive electrode terminal 110 and the positive electrode tab 312a, a momentary interruption between the electrode body 311 and the positive electrode tab 312a, a momentary interruption between the cylindrical can 200 and the negative electrode tab 312b, a momentary interruption between the electrode body 311 and the negative electrode tab 312b, a momentary interruption between the contact surfaces and the contact resistance increases, and the output voltage from the battery decreases and chattering does not occur easily. On the other hand, the battery cell 310 covered with the shock absorbing material 320 moves in the vertical direction due to the impact, so that the directly connected parts may come off and be damaged. In contrast, the folded shapes of the positive electrode tab 312a and the negative electrode tab 312b deform in response to movement and displacement (distortion), thereby improving the impact resistance of the welded or brazed portions (directly connected portions) against impact.

[0094] <Manufacturing method for all-solid-state batteries> A method for manufacturing the all-solid-state battery according to the first embodiment will be described. First, a metal cap 100, a cylindrical can 200, an electrode body 311, an impact absorbing material 320, and straight plate-like positive electrode tabs 312a and negative electrode tabs 312b are prepared. The positive electrode tab 312a is bent at two predetermined bending points P1 and P2 to a provisionally bent state, and is further bent at a predetermined location to secure the joining target portions of one end and the other end. The negative electrode tab 312b is bent at two predetermined bending points P11 and P12 to a provisionally bent state, and is further bent at a predetermined location to secure the joining target portions of one end and the other end. The impact absorbing material 320 is attached to the electrode body 311.

[0095] 9A to 9F, the metal cap 100 is stacked on the battery cell 300 with the shock absorbing material via the positive electrode tab 312a, and the assembly is stacked on the cylindrical can 200 via the negative electrode tab 312b. Finally, the metal cap 100, the battery cell 300 with the shock absorbing material, and the cylindrical can 200, which are assembled so as to be stacked on each other via the positive electrode tab 312a and the negative electrode tab 312b, are combined to produce an all-solid-state battery. The power supply tab 312 has a folded shape that is folded back in opposite directions alternately at multiple bending points, which enables such stacking and assembly.

[0096] 9A to 9F will be described in detail below. As shown in Fig. 9A, the other end of the pre-bent positive electrode tab 312a to be joined is joined to the positive electrode terminal 110 of the metal cap 100 by welding (laser welding, spot welding, etc.), brazing, etc., and then the metal cap 100 is stacked on the battery cell 300 with the shock absorbing material via the positive electrode tab 312a, and the one end of the pre-bent positive electrode tab 312a to be joined is joined to the positive electrode side of the electrode body 311 to which the shock absorbing material 320 is attached by welding (laser welding, spot welding, etc.), brazing, etc.

[0097] Next, as shown in Figures 9B and 9C, the assembled part of Figure 9A is placed above the cylindrical can 200, and the joining target portion of the other end of the negative electrode tab 312b in the provisionally bent state is joined to the negative electrode side surface of the electrode body 311 of the assembled part of Figure 9A by welding (laser welding, spot welding, etc.), brazing, etc. Thereafter, as shown in Figure 9D, the joining target portion of one end of the negative electrode tab 312b in the provisionally bent state is joined to the bottom surface of the cylindrical can 200 by welding (laser welding, spot welding, etc.), brazing, etc., and the assembled part (excluding the cylindrical can 200) in the state shown in Figure 9C is stacked on the cylindrical can 200 via the negative electrode tab 312b.

[0098] 9E, the metal cap 100, the electrode assembly 311 to which the shock absorbing material 320 is attached, the cylindrical can 200, the positive electrode tab 312a, and the negative electrode tab 312b are aligned so that the positive electrode tab 312a, the electrode assembly 311 to which the shock absorbing material 320 is attached, and the negative electrode tab 312b are disposed between the metal cap 100 and the cylindrical can 200. Then, the cylindrical can 200 and the metal cap 100 are combined by applying force to at least one of the metal cap 100 and the cylindrical can 200 (for example, applying force to the metal cap 100 and the cylindrical can 200 from above and below as shown by the white arrow) so that the distance between the metal cap 100 and the cylindrical can 200 is shortened.

[0099] As a result, the pre-bent positive electrode tab 312a is bent to the state shown in FIG. 9F, and the pre-bent negative electrode tab 312b is bent to the state shown in FIG. 9F, and the metal cap 100 and the cylindrical can 200 are combined (mated) together, completing the all-solid-state battery according to the first embodiment as shown in FIG. 9F.

[0100] In each of the above embodiments, the all-solid-state battery may be configured so that the cylindrical can 200 functions as a positive terminal, and the positive terminal 110 or the metal cap 100 in which the opening 101 is not formed functions as a negative terminal. In this case, the battery cell 310 is turned upside down so that the positive tab 312a is disposed on the cylindrical can 200 side and the negative tab 312b is disposed on the metal cap 100 side, and the positive tab 312a is connected to the cylindrical can 200 and the negative tab 312b is connected to the positive terminal 110 or the metal cap 100 in which the opening 101 is not formed. In this modified example, the "positive terminal 110" is newly changed to the "negative terminal 110".

[0101] <Effects> As described above, the all-solid-state battery according to the first embodiment of the present invention has a configuration in which the shock absorbing material 320 is attached to the electrode body 311 of the battery cell 310 so as to cover a part of the electrode body 311. Therefore, when an impact is applied to the all-solid-state battery, the shock is absorbed by the shock absorbing material 320, and the impact applied to the electrode body 311 can be alleviated. Furthermore, in the all-solid-state battery according to the first embodiment, the positive electrode tab 312a and the negative electrode tab 312b have a specific folded shape, and when an impact is applied to the all-solid-state battery, the positive electrode tab 312a and the negative electrode tab 312b change shape in accordance with the displacement (distortion) of the electrode body 311 to absorb the impact, and the impact applied to the electrode body 311 can be alleviated. Furthermore, in the all-solid-state battery according to the first embodiment, the positive electrode tab 312a and the negative electrode tab 312b have a specific folded shape, and therefore, ... the impact resistance of the welded or brazed portion (direct connection portion) against impact can be improved. As a result, the impact resistance of the all-solid-state battery according to the first embodiment can be improved.

[0102] The all-solid-state battery according to the first embodiment of the present invention can be used in the same applications as conventionally known primary batteries and secondary batteries, but since it has a solid electrolyte instead of an organic electrolyte solution, it has excellent heat resistance and can be preferably used in applications where it is exposed to high temperatures.

[0103] <<Second embodiment>> The all-solid-state battery according to the second embodiment of the present invention will be described. The all-solid-state battery according to the second embodiment differs from the all-solid-state battery according to the first embodiment only in that the shape of the shock absorbing material 320 is different from that of the shock absorbing material 320 according to the first embodiment. The following description will focus on this difference.

[0104] Fig. 10 is a perspective view of a battery cell with shock absorbing materials of an all-solid-state battery according to the second embodiment. Fig. 11 is an exploded perspective view of the battery cell with shock absorbing materials according to the second embodiment.

[0105] 10 and 11, the battery cell 300 with shock absorbing material includes a battery cell 310 and a shock absorbing material 320. The battery cell 300 with shock absorbing material is a component in which the shock absorbing material 320 is attached to the battery cell 310.

[0106] The impact absorbing material 320 has a generally cylindrical shape with only one end face or one end face and the other end face open, and with the side faces partially open, and has a shape including a first annular portion 320d, a second annular portion 320e facing the first annular portion 320d with a gap therebetween, and a first side portion 320f1, a second side portion 320f2, a third side portion 320f3, and a fourth side portion 320f4 provided at equal intervals on the side faces. In the following description, the first side portion 320f1 to the fourth side portion 320f4 are referred to as "side portion 320f" when there is no need to particularly distinguish between them.

[0107] The inner surface of the side portion 320f has a concave groove shape. The groove shape includes a bottom portion 320g of the groove, a third wall portion 320h extending inward from the bottom portion 320g, and a fourth wall portion 320i facing the third wall portion 320h and extending inward from the bottom portion 320g approximately parallel to the third wall portion 320h. The third wall portion 320h is integrally connected to the inner surface of the first annular portion 320d so as to be flush with the inner surface of the second annular portion 320e, and the fourth wall portion 320i is integrally connected to the inner surface of the second annular portion 320e so as to be flush with the inner surface of the second annular portion 320e.

[0108] The impact absorbing material 320 is shaped so that the electrode body 311 of the battery cell 310 fits into a space SP2 surrounded by the first annular portion 320d, the second annular portion 320e, and the first side portion 320f1 to the fourth side portion 320f4, and the impact absorbing material 320 is shaped so that it can be attached to the battery cell 310 such that the electrode body 311 covers the peripheral edge of the positive electrode side and the peripheral edge of the negative electrode side of the electrode body 311 while avoiding the contact portions with the power supply tab 312 of the electrode body 311 (contact portions with the power supply tab 312 on the positive electrode side and the negative electrode side), and also partially covers the sides of the electrode body 311.

[0109] The peripheral ends and sides of the positive and negative electrode sides of the electrode body 311 of the battery cell 310 are inserted between the "first circular ring portion 320d and third wall portion 320h" and the "second circular ring portion 320e and fourth wall portion 320i" of the impact absorbing material 320, and the sides of the electrode body 311 partially face the bottoms 320g of the grooves of the first side portion 320f1 to the fourth side portion 320f4 with a small gap therebetween, and the opposing "first circular ring portion 320f2 and third wall portion 320h" and "second circular ring portion 320e and fourth wall portion 320i" of the impact absorbing material 320. The battery cell 310 is disposed in the space SP2 in a state in which the "first circular ring portion 320d and the third wall portion 320h" and the "second circular ring portion 320e and the fourth wall portion 320i" are in contact with the peripheral end of the positive electrode side surface and the peripheral end of the negative electrode side surface of the electrode body 311, and the peripheral end of the positive electrode side surface and the peripheral end of the negative electrode side surface of the electrode body 311 are sandwiched between the "first circular ring portion 320d and the third wall portion 320h" and the "second circular ring portion 320e and the fourth wall portion 320i". The contact portions of the positive electrode tab 312a and the negative electrode tab 312b of the battery cell 310 disposed in the space SP2 are not covered by the impact absorbing material 320.

[0110] In this state, when the shock absorbing material 320 is attached to the battery cell 310, the shock absorbing material 320 avoids the contact portion with the power supply tab 312 of the electrode body 311, and covers the peripheral end portion of the positive electrode side surface and the peripheral end portion of the negative electrode side surface of the electrode body 311 of the battery cell 310, as well as parts of the side surfaces of the electrode body 311, with the first circular ring portion 320d, the second circular ring portion 320e, and the first side portion 314f1 to the fourth side portion 314f4 of the shock absorbing material 320. In this way, the shock absorbing material 320 can absorb the shock applied to the electrode body 311 of the battery cell 310 and reduce the shock applied to the electrode body 311.

[0111] The shock absorbing material 320 has a shape that is more easily deformed than the shock absorbing material 320 of the first embodiment by forming gaps between the first annular portion 320d and the second annular portion 320e and between each side portion 320f. Therefore, when an impact is applied to the all-solid-state battery, the shock absorbing material 320 absorbs the impact, thereby reducing the impact applied to the electrode body 311 of the battery cell 310, and the shock absorber 320 receives the impact due to deformation of the shock absorbing material 320 that follows the displacement (distortion) of the electrode body 311 due to the impact, thereby reducing the impact applied to the electrode body 311. Therefore, the shock absorbing material 320 of the second embodiment has higher shock absorbing properties than the shock absorbing material 320 of the first embodiment. As a result, the all-solid-state battery according to the second embodiment can have improved impact resistance compared to the first embodiment. Furthermore, in the all-solid-state battery according to the second embodiment, similarly to the first embodiment, when the impact absorbing material 320 is attached to the battery cell 310, the impact absorbing material 320 covers a part of the battery cell 310 while avoiding the contact portion with the power supply tab 312 of the electrode body 311, so that it is possible to improve impact resistance without interfering with the electrical connection between the electrode body 311 and the power supply tab 312.

[0112] <Effects> As described above, the all-solid-state battery according to the second embodiment of the present invention has the same effects as the first embodiment, and further has improved impact resistance compared to the first embodiment.

[0113] <<Modifications>> The present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention. Furthermore, the above-described embodiments can be combined with each other without departing from the scope of the present invention.

[0114] The numerical values, structures, shapes, materials, raw materials, manufacturing processes, etc. described in each of the above embodiments are merely examples, and numerical values, structures, shapes, materials, raw materials, manufacturing processes, etc. different from these may be used as necessary.

[0115] The configurations, methods, steps, shapes, materials, numerical values, etc. of the above-described embodiments can be combined with each other without departing from the scope of the present invention.

[0116] In each of the above embodiments, the folded shape of the positive electrode tab 312a and the folded shape of the negative electrode tab 312b may be different from each other. When the positive electrode tab 312a and the negative electrode tab 312b are made of the same material and have the same width and length, it is preferable that the folded shape of the positive electrode tab 312a and the folded shape of the negative electrode tab 312b are the same from the viewpoint of ensuring a balance in rigidity.

[0117] In each of the above embodiments, the number of folds (the number of bending points) may be increased or decreased depending on the width of the power supply tab 312. For example, when the power supply tab 312 is made of the same material, the stiffness of the power supply tab 312 tends to increase as the width increases, and the stiffness of the power supply tab 312 tends to decrease as the width decreases. For this reason, when the stiffness of the positive electrode tab 312a and the negative electrode tab 312b differs from each other due to differences in width between the positive electrode tab 312a and the negative electrode tab 312b, the number of bending points of the positive electrode tab 312a and the negative electrode tab 312b may be made different from each other in order to ensure a balance in stiffness. For example, when the width of the positive electrode tab 312a is larger than that of the negative electrode tab 312b, the number of bending points of the positive electrode tab 312a may be made larger than the number of bending points of the negative electrode tab 312b, so as to balance the stiffness of the positive electrode tab 312a and the negative electrode tab 312b.

[0118] In each of the above embodiments, instead of the exterior body composed of the metal cap 100 and the cylindrical can 200 having an opening, other exterior bodies such as a laminate film exterior body composed of a metal laminate film such as an aluminum laminate film can be used.

[0119] In each of the above embodiments, the positive electrode terminal 110 and the gasket 120 may be omitted, and the metal cap 100 in which the opening 101 is not formed may be insulated from the cylindrical can 200 by a gasket, so that the metal cap 100 itself functions as the positive electrode terminal. In this case, the other end of the positive electrode tab 312a is welded or brazed to the metal cap 100 (for example, a region of the metal cap 100 facing the positive electrode side surface of the electrode body 311).

[0120] In the technology according to the present embodiment, the battery cells are sealed and housed in a cylindrical can with shock absorbing material between them, which prevents the battery cells from reacting with moisture in the air and improves shock resistance. The present invention provides such technology and can contribute to the achievement of the 9th Sustainable Development Goal (SDGs) proposed by the United Nations, "Build resilient infrastructure and promote inclusive and sustainable industrialization." [Explanation of symbols]

[0121] 100...metal cap, 110...positive electrode terminal, 120...gasket, 200...cylindrical can, 300...battery cell with shock absorbing material, 310...battery cell, 311...electrode body, 312a...positive electrode tab, 312b...negative electrode tab, 320...shock absorbing material

Claims

1. a battery cell including an electrode body having a positive electrode, a negative electrode, and a solid electrolyte interposed between the positive electrode and the negative electrode, the electrode body having a positive electrode side and a negative electrode side, a positive electrode tab attached to the positive electrode side of the electrode body, and a negative electrode tab attached to the negative electrode side of the electrode body; an elastic member attached to the battery cell so as to cover a portion of the electrode assembly; an exterior body in which a space is formed and in which the battery cell with the elastic member attached is housed; Equipped with Each of the positive electrode tab and the negative electrode tab has a folded shape folded back at one bending point or a folded shape folded back in opposite directions alternately at a plurality of bending points. All-solid-state battery.

2. The all-solid-state battery according to claim 1 , The exterior body is composed of a first exterior part that functions as a negative electrode terminal and a second exterior part that includes a positive electrode terminal, the battery cell is disposed between the first exterior part and the second exterior part, One end of the positive electrode tab is welded or brazed to the positive electrode side surface of the electrode body, and the other end of the positive electrode tab is welded or brazed to the positive electrode terminal in an area facing the positive electrode side surface, One end of the negative electrode tab is welded or brazed to a region of the first exterior part facing the negative electrode side surface, and the other end of the negative electrode tab is welded or brazed to the negative electrode side surface of the electrode body. All-solid-state battery.

3. The all-solid-state battery according to claim 1 , The exterior body includes a first exterior part that functions as a negative electrode terminal and a second exterior part that functions as a positive electrode terminal, the battery cell is disposed between the first exterior part and the second exterior part, one end of the positive electrode tab is welded or brazed to the positive electrode side surface of the electrode body, and the other end of the positive electrode tab is welded or brazed to a region of the second exterior portion facing the positive electrode side surface, One end of the negative electrode tab is welded or brazed to a region of the negative electrode side surface of the first exterior part facing the negative electrode side surface, and the other end of the negative electrode tab is welded or brazed to the negative electrode side surface of the electrode body. All-solid-state battery.

4. The all-solid-state battery according to claim 1 , The elastic member is a shock absorbing material, the impact absorbing material covers a part of the electrode body while avoiding a contact portion of the positive electrode side surface with the positive electrode tab and a contact portion of the negative electrode side surface with the negative electrode tab; All-solid-state battery.

5. The all-solid-state battery according to claim 1 , The electrode body has a shape including the positive electrode side surface and the negative electrode side surface facing each other, and a side surface between the positive electrode side surface and the negative electrode side surface, The elastic member is a shock absorbing material, The impact absorbing material covers a portion of the electrode body including at least a peripheral end of the positive electrode side surface, a peripheral end of the negative electrode side surface, and a portion of the side surface. All-solid-state battery.

6. The all-solid-state battery according to claim 5 , The exterior body is composed of a metal cylindrical can having an opening, and a metal cap including a positive electrode terminal and a gasket, the metal cap being combined with the cylindrical can to close the opening of the cylindrical can, the battery cell is disposed between the cylindrical can and the metal cap; the positive electrode tab is disposed between the metal cap and the positive electrode side of the electrode body; The negative electrode tab is disposed between the bottom surface of the cylindrical can and the negative electrode side surface of the electrode body. All-solid-state battery.

7. The all-solid-state battery according to claim 6, One end of the positive electrode tab is welded or brazed to the positive electrode side surface of the electrode body, and the other end of the positive electrode tab is welded or brazed to the positive electrode terminal, One end of the negative electrode tab is welded or brazed to the bottom surface of the cylindrical can, and the other end of the negative electrode tab is welded or brazed to the negative electrode side surface of the electrode body. All-solid-state battery.

8. The all-solid-state battery according to claim 7, The positive electrode tab is in a state where a part of a surface of the positive electrode tab, including a welded or brazed portion, is in contact with a surface of the positive electrode terminal, The negative electrode tab is in a state where a part of a surface of the negative electrode tab, including a welding or brazing portion, is in contact with a surface of the cylindrical can. All-solid-state battery.

9. The all-solid-state battery according to claim 7, The impact absorbing material covers, as a part of the electrode body, a peripheral end of the positive electrode side surface of the electrode body, a peripheral end of the negative electrode side surface of the electrode body, and the side surface of the electrode body. All-solid-state battery.

10. The all-solid-state battery according to claim 7, The impact absorbing material, as a part of the electrode body, covers a peripheral end of the positive electrode side surface of the electrode body, a peripheral end of the negative electrode side surface of the electrode body, and a part of the side surface of the electrode body. All-solid-state battery.

11. The all-solid-state battery according to claim 7, each of the positive electrode tab and the negative electrode tab has a folded shape that is folded in opposite directions alternately at a plurality of bending points; The folded shape is a folded shape folded in opposite directions alternately at three bending points. All-solid-state battery.

12. The all-solid-state battery according to claim 1 , The positive electrode tab and the negative electrode tab have the same shape. All-solid-state battery.

13. The all-solid-state battery according to claim 1 , The positive electrode tab and the negative electrode tab have different shapes. All-solid-state battery.

14. The all-solid-state battery according to claim 13, The width of the positive electrode tab and the width of the negative electrode tab are different, The number of bending points of the positive electrode tab and the negative electrode tab, whichever has a longer width, is made greater than the number of bending points of the tab, which has a shorter width. All-solid-state battery.

15. The all-solid-state battery according to claim 1 , The battery cell includes: the electrode body includes a battery molded body in which a positive electrode side layer including a positive electrode layer including a positive electrode material constituting the positive electrode, a negative electrode side layer including a negative electrode layer including a negative electrode material constituting the negative electrode, and a solid electrolyte layer including a solid electrolyte material constituting the solid electrolyte are laminated such that the solid electrolyte layer is interposed between the positive electrode side layer and the negative electrode side layer; All-solid-state battery.

16. a battery cell including an electrode body having a positive electrode, a negative electrode, and a solid electrolyte interposed between the positive electrode and the negative electrode, the electrode body having a positive electrode side and a negative electrode side, a positive electrode tab attached to the positive electrode side of the electrode body, and a negative electrode tab attached to the negative electrode side of the electrode body; an impact absorbing material attached to the battery cell so as to cover a portion of the electrode assembly; an exterior body including a cylindrical can serving as a negative terminal in which a space is formed and in which the battery cell with the shock absorbing material attached is housed, and a metal cap including a positive terminal or functioning as a positive terminal; Equipped with Each of the positive electrode tab and the negative electrode tab has a folded shape folded back at one bending point or a folded shape folded back in opposite directions alternately at a plurality of bending points. A method for producing an all-solid-state battery, comprising: one end of the positive electrode tab is joined to the positive electrode side surface of the electrode body to which the impact absorbing material is attached by welding or brazing, and the other end of the positive electrode tab in a pre-bent state is joined to the positive electrode terminal of the metal cap or to the metal cap that functions as a positive electrode terminal by welding or brazing; one end of the negative electrode tab in a pre-bent state is joined to a bottom surface of the cylindrical can by welding or brazing, and the other end of the negative electrode tab is joined to the negative electrode side surface of the electrode body to which the impact absorbing material is attached by welding or brazing; Aligning the metal cap and the cylindrical can so that the positive electrode tab, the electrode body, and the negative electrode tab are disposed between the metal cap and the cylindrical can; applying a force to at least one of the metal cap and the cylindrical can so as to reduce a distance between the metal cap and the cylindrical can, thereby combining the metal cap and the cylindrical can, and bending the positive electrode tab in a pre-bent state and bending the negative electrode tab in a pre-bent state to form the folded-back shape; Including, How solid-state batteries are manufactured.

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