Manufacturing method of all-solid battery

Abstract

To provide a manufacturing method of an all-solid battery capable of suppressing damage of a tab, which extends from a collector when welding the tab and a lead in an ultrasonic manner.SOLUTION: A manufacturing method of an all-solid battery 1 includes: a lamination step of laminating a plurality of cells 2, a plurality of cathode collectors 3A and a plurality of anode collectors 3B; a cathode tab fixing step of folding a cathode tab 312A, forming a cathode first portion 3121A extending along a side face of a laminate L2, a cathode second portion 3122A extending in a direction away from the laminate L2 and a cathode bending portion 3123A and fixing the entire cathode first portion 3121A to the laminate L2; and a cathode welding step of welding the entire cathode second portion 3122A to a cathode lead 4 in an ultrasonic manner in a state where the entire cathode first portion 3121A is fixed to the laminate L2.SELECTED DRAWING: Figure 10

Description

[Technical field]

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

[0002] Conventionally, a stacked battery has been known which includes a stacked electrode body in which a positive electrode plate having positive electrode active material layers on both sides, a negative electrode plate having negative electrode active material layers on both sides, and a separator arranged between the positive electrode plate and the negative electrode plate, in which a positive electrode current collector lead extending from the positive electrode plate is joined to a positive electrode current collector terminal, and a negative electrode current collector lead extending from the negative electrode plate is joined to a negative electrode current collector terminal (see Patent Document 1 below).

[0003] In the above-mentioned manufacturing method for a stacked battery, when multiple positive electrode collector leads are joined to a positive electrode collector terminal, the multiple positive electrode collector leads are focused on one side in the stacking direction of the stacked electrode body using a focusing head, and then the tips of the focused multiple positive electrode collector leads are ultrasonically welded to the positive electrode collector terminal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-164470 A Summary of the Invention [Problem to be solved by the invention]

[0005] In manufacturing a stacked battery as described in Patent Document 1, for example, when it is desired to prevent the stacked battery from becoming large, the positive electrode current collector lead and the positive electrode current collector terminal are welded to each other at a position close to the stacked electrode body.

[0006] However, in the manufacturing method described in Patent Document 1, the focusing head is removed during ultrasonic welding.

[0007] For this reason, when welding the positive electrode current collector lead and the positive electrode current collector terminal, it may be necessary to perform ultrasonic welding while holding the positive electrode current collector lead to be restored with an ultrasonic horn.

[0008] If the positive collector lead to be restored is ultrasonically welded while being held down with an ultrasonic horn, the portion of the positive collector lead that is being held down by the edge of the ultrasonic horn may be damaged.

[0009] The present invention provides a method for manufacturing an all-solid-state battery that can suppress breakage of a tab extending from a current collector when ultrasonically welding the tab to a lead. [Means for solving the problem]

[0010] The present invention [1] provides a method for manufacturing a battery comprising the steps of: laminating, in the first direction, a plurality of cells each having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer; a plurality of positive electrode current collectors each having a positive electrode laminated portion laminated on the positive electrode layer of the cell and a positive electrode tab extending from the positive electrode laminated portion; and a plurality of negative electrode current collectors each having a negative electrode laminated portion laminated on the negative electrode layer of the cell and a negative electrode tab extending from the negative electrode laminated portion; and bending at least one of the positive electrode tabs to form a positive electrode first portion extending in the first direction along a side surface of the laminate of the cell, the positive electrode laminated portion, and the negative electrode laminated portion, a positive electrode second portion extending in a second direction away from the laminate, and a positive electrode bent portion connecting the positive electrode first portion and the positive electrode second portion; the negative electrode tab fixing step of bending at least one of the negative electrode tabs to form a negative electrode first portion extending in the first direction along a side surface of the laminate, a negative electrode second portion extending in a second direction away from the laminate, and a negative electrode bent portion connecting the negative electrode first portion and the negative electrode second portion, thereby fixing all of the negative electrode first portions to the laminate; a positive electrode welding step of ultrasonically welding all of the positive electrode second portions to a positive electrode lead with all of the positive electrode first portions fixed to the laminate; and a negative electrode welding step of ultrasonically welding all of the negative electrode second portions to a negative electrode lead with all of the negative electrode first portions fixed to the laminate.

[0011] According to this method, before ultrasonic welding the positive electrode tab and the positive electrode lead, the positive electrode tab is bent to form a positive electrode first portion, a positive electrode second portion, and a positive electrode bent portion. The positive electrode first portion extends in the stacking direction (first direction) of the multiple cells along a side surface of a stack in which multiple cells are stacked. The positive electrode second portion extends in a direction away from the stack (second direction). The positive electrode bent portion connects the positive electrode first portion and the positive electrode second portion.

[0012] Then, in a positive electrode welding step, the positive electrode second portion is ultrasonically welded to the positive electrode lead in a state in which the positive electrode first portion is fixed to the laminate.

[0013] By fixing the positive electrode first portion to the laminate, restoration of the positive electrode tab in the positive electrode welding step is suppressed, and therefore it is not necessary to hold the positive electrode tab attempting to restore its shape with the horn of an ultrasonic welding device.

[0014] Therefore, damage to the positive electrode tab by the edge of the horn can be suppressed.

[0015] As a result, when the positive electrode tab and the positive electrode lead are ultrasonically welded together, it is possible to prevent the positive electrode tab from being damaged. The same applies when the negative electrode tab and the negative electrode lead are ultrasonically welded together.

[0016] The present invention [2] includes the method for manufacturing an all-solid-state battery of the above [1], wherein the positive electrode tab fixing step and the negative electrode tab fixing step are performed by covering the stack with a fixing member having a recess capable of accommodating the stack, and fixing all of the positive electrode first portions and all of the negative electrode first portions to the stack by an inner surface of the recess, and the positive electrode welding step and the negative electrode welding step are performed in a state in which the fixing member is covered with the stack.

[0017] According to this method, the positive electrode first portion and the negative electrode first portion can be fixed to the laminate by the simple method of covering the laminate with a fixing member having a recess.

[0018] As a result, the stack can be protected by the fixing member, and an all-solid-state battery can be produced efficiently.

[0019] The present invention [3] includes the method for producing an all-solid-state battery according to the above [2], wherein the fixing member is an exterior material of the all-solid-state battery.

[0020] According to this method, the exterior material of the all-solid-state battery can be used as the fixing member.

[0021] Therefore, the laminate can be handled in a state in which it is placed in the exterior packaging material, and further, after the positive electrode welding step and the negative electrode welding step, the laminate can be packaged using the exterior packaging material that was used as a fixing member.

[0022] As a result, all-solid-state batteries can be produced efficiently.

[0023] The present invention [4] includes the method for producing an all-solid-state battery according to any one of the above [1] to [3], wherein, in the positive electrode tab fixing step, all of the positive electrode first portions are fixed to the laminate with an adhesive tape, and, in the negative electrode tab fixing step, all of the negative electrode first portions are fixed to the laminate with an adhesive tape.

[0024] The present invention [5] includes the method for manufacturing an all-solid-state battery according to any one of the above [1] to [4], wherein, in the positive electrode welding step, a horn of an ultrasonic welding device does not come into contact with the positive electrode bent portion but comes into contact with the positive electrode second portion, and, in the negative electrode welding step, a horn of an ultrasonic welding device does not come into contact with the negative electrode bent portion but comes into contact with the negative electrode second portion.

[0025] According to this method, damage to the positive electrode tab and the negative electrode tab by the edge of the horn can be prevented.

[0026] The present invention [6] includes the method for producing an all-solid-state battery according to any one of the above [1] to [5], wherein the positive electrode layer is made from a powder containing a positive electrode active material, the negative electrode layer is made from a powder containing a negative electrode active material, and the solid electrolyte layer is made from a powder of a solid electrolyte, and the method for producing the all-solid-state battery further includes, before the lamination step, a cell formation step of forming the cell on a first substrate by a dry process, a pressing step of laminating a second substrate on the cell and pressing the obtained laminate, and a peeling step of peeling off at least one of the first substrate and the second substrate from the cell.

[0027] According to this method, cells formed by a dry process on a first substrate are pressed between the first substrate and a second substrate to solidify them, and then at least one of the first substrate and the second substrate is peeled off and laminated.

[0028] This allows the production of an all-solid-state battery having cells produced by the dry process.

[0029] Therefore, compared to an all-solid-state battery having a cell manufactured by a wet method, the obtained all-solid-state battery suppresses the decrease in power generation efficiency caused by voids that occur in the cell when the solvent evaporates and by resins such as binders.

[0030] As a result, the method for producing an all-solid-state battery of the present invention can improve the energy density of the produced all-solid-state battery.

[0031] The present invention [7] includes the method for producing an all-solid-state battery according to any one of the above [1] to [6], wherein the lamination step includes a first step of laminating a first cell on the positive electrode current collector such that the positive electrode layer of the first cell is in contact with the positive electrode current collector, a second step of laminating the negative electrode current collector on the negative electrode layer of the first cell following the first step, and a third step of laminating a second cell on the negative electrode current collector such that the negative electrode layer of the second cell is in contact with the negative electrode current collector following the second step.

[0032] According to this method, it is possible to manufacture a bi-cell type all-solid-state battery in which the first cell and the second cell are in contact with one current collector.

[0033] The present invention [8] includes the method for producing an all-solid-state battery according to any one of the above [1] to [7], wherein the positive electrode current collector and the negative electrode current collector have a conductor and an insulating member laminated on a peripheral portion of the conductor, and in the lamination step, the cell is laminated on the conductor.

[0034] According to this method, a positive electrode current collector and a negative electrode current collector having an insulating member laminated on the peripheral portion of a conductor are used, so that an all-solid-state battery can be manufactured through a simple process of laminating a cell, a positive electrode current collector, and a negative electrode current collector.

[0035] The present invention [9] includes the method for producing an all-solid-state battery according to the above [8], further comprising an adhesive layer in which the insulating member is laminated on one side of the conductor, and the positive electrode current collector and the negative electrode current collector are laminated on the other side of the conductor at the peripheral portion of the conductor.

[0036] According to such a method, for example, when a cell is stacked on a positive electrode current collector and then a negative electrode current collector is stacked on the cell, the adhesive layer of the negative electrode current collector can be adhered to the insulating member of the positive electrode current collector.

[0037] This makes it possible to suppress short-circuiting between the positive electrode current collector and the negative electrode current collector.

[0038] The present invention

[10] includes the method for manufacturing an all-solid-state battery according to the above [8] or [9], wherein the positive electrode current collector and the negative electrode current collector have a notch cut from an edge of the conductor to the inside of the insulating member, and in the stacking step, a jig is placed in the notch to position the cell with respect to the positive electrode current collector or the negative electrode current collector so that an edge of the cell contacts the jig.

[0039] According to such a method, the cells, the positive electrode current collectors, and the negative electrode current collectors can be easily stacked while preventing the position of the cells from being shifted relative to the positive electrode current collectors or the negative electrode current collectors. Effect of the Invention

[0040] According to the manufacturing method for an all-solid-state battery of the present invention, it is possible to suppress breakage of the tab extending from the current collector when ultrasonically welding the tab and the lead. [Brief description of the drawings]

[0041] [Figure 1] Fig. 1A is a plan view of an all-solid-state battery according to one embodiment of the present invention, and Fig. 1B is a cross-sectional view taken along line AA of the all-solid-state battery shown in Fig. 1A. [Diagram 2] Fig. 2A is a cross-sectional view showing the layer structure of the cell shown in Fig. 1B, and Fig. 2B is an enlarged view of the all-solid-state battery shown in Fig. 1B. [Diagram 3] Fig. 3A is a plan view of the positive electrode current collector shown in Fig. 2B, and Fig. 3B is a cross-sectional view taken along line BB of the positive electrode current collector shown in Fig. 3A. [Figure 4] FIG. 4 is a cross-sectional view taken along CC of the all-solid-state battery shown in FIG. 1A. [Diagram 5]5A and 5B are process diagrams illustrating a method for manufacturing an all-solid-state battery. Fig. 5A shows a state in which the opening of the screen is filled with a positive electrode mixture in the cell formation process. Fig. 5B shows a state in which the positive electrode mixture in the opening is transferred onto a first substrate to form a positive electrode layer on the first substrate in the cell formation process. [Figure 6] 6A to 6C are process diagrams illustrating the manufacturing method of an all-solid-state battery following FIG. 5B. FIG. 6A shows a state in which a solid electrolyte layer is formed on a positive electrode layer and a negative electrode layer is formed on the solid electrolyte layer in a cell formation process. FIG. 6B shows a pressing process. FIG. 6C shows a peeling process. [Figure 7] 7A and 7B are process diagrams illustrating the manufacturing method of the all-solid-state battery following FIG. 6C. FIG. 7A shows a state in which the first cell is stacked on the positive electrode current collector in the stacking process. FIG. 7B shows a state in which the first cell is positioned relative to the positive electrode current collector in the first orthogonal direction in the stacking process. [Figure 8] 8A and 8B are process diagrams illustrating a method for manufacturing an all-solid-state battery, following FIG. 7B. FIG. 8A shows a state in which a first cell is positioned relative to a positive electrode current collector in a second orthogonal direction in a stacking step. FIG. 8B shows a state in which a negative electrode current collector is stacked on the first cell, and a second cell is stacked on the negative electrode current collector in a stacking step. [Figure 9] 9A and 9B are process diagrams for explaining the manufacturing method of the all-solid-state battery following FIG. 8B. FIG. 9A shows a state in which the second cell is positioned relative to the negative electrode current collector in the first orthogonal direction in the stacking process. FIG. 9B shows a state in which the second cell is positioned relative to the negative electrode current collector in the second orthogonal direction in the stacking process. [Figure 10] 10A to 10C are process diagrams illustrating the manufacturing method of the all-solid-state battery following FIG. 9B. FIG. 10A shows a state in which the positive electrode tab is folded in the positive electrode tab fixing step. FIG. 10B shows a state in which the positive electrode tab is fixed to the laminate by a fixing member in the positive electrode tab fixing step. FIG. 10C shows a positive electrode tab welding step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] 1.All-solid-state battery The all-solid-state battery 1 will be described.

[0043] As shown in FIGS. 1A and 1B, the all-solid-state battery 1 includes a plurality of cells 2, a plurality of current collectors 3, a positive electrode lead 4, a negative electrode lead 5, and an exterior material 6.

[0044] (1) Cell In this embodiment, the cell 2 has a sheet shape. When viewed from the thickness direction of the cell 2, the cell 2 has a substantially rectangular shape. The shape of the cell 2 is not limited. The cell 2 may have a plate shape or a film shape. Also, the cell 2 may have a substantially circular shape when viewed from the thickness direction of the cell 2.

[0045] The thickness of the cell 2 is, for example, 100 μm or more, preferably 200 μm or more, and for example, 1000 μm or less, preferably 800 μm or less.

[0046] 2A, the cell 2 has a positive electrode layer 21, a negative electrode layer 22, and a solid electrolyte layer 23. The cell 2 is a bare cell. The cell 2 is composed of the positive electrode layer 21, the negative electrode layer 22, and the solid electrolyte layer 23. The cell 2 does not have a current collector.

[0047] (1-1) Positive electrode layer The positive electrode layer 21 is disposed away from the negative electrode layer 22 in the thickness direction of the cell 2. The positive electrode layer 21 is disposed on the opposite side of the negative electrode layer 22 with respect to the solid electrolyte layer 23 in the first direction. The positive electrode layer 21 is in contact with the solid electrolyte layer 23 and is not in contact with the negative electrode layer 22.

[0048] The positive electrode layer 21 is made of a powder containing a positive electrode active material. In this embodiment, the positive electrode layer 21 does not contain a resin such as a binder. In this embodiment, the positive electrode layer 21 is made of a mixture of a powder of the positive electrode active material and a powder of a solid electrolyte. The positive electrode layer 21 does not have to contain a solid electrolyte. The positive electrode layer 21 may be made of only the positive electrode active material.

[0049] The positive electrode active material may be, for example, a lithium-containing oxide. The lithium-containing oxide may, for example, be a lithium-nickel composite oxide (LiNi X M 1-X O2), lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium nickel cobalt aluminum oxide (LiNi 0.8 Co 0.15 Al 0.05 O2, NCA-based layered oxide), lithium manganate (spinel-type lithium manganate (LiMn2O4)), and Li-excess composite oxide (Li2MnO3-LiMO2).

[0050] The positive electrode active material is not limited to lithium-containing oxides as long as it is capable of inserting and extracting lithium ions. Examples of the positive electrode active material include olivine compounds (LiMPO4) and sulfur-containing compounds (Li2S).

[0051] In the above chemical formula, M represents a transition metal.

[0052] As the positive electrode active material, from the viewpoint of easily obtaining a high capacity, a lithium-containing oxide containing at least one selected from the group consisting of Co, Ni, and Mn is preferably used.

[0053] In addition, from the viewpoint of improving rate characteristics, the surface of the positive electrode active material may be covered with a coating material.

[0054] Coating materials include, for example, Li4Ti5O 12, LiTaO3, Li4NbO3, LiAlO2, Li2ZrO3, Li2WO4, Li2TiO3, Li2B4O7, Li3PO4, Li2MoO4, LiBO2, alumina (Al2O3), and carbon (C).

[0055] The positive electrode active materials can be used alone or in combination of two or more kinds.

[0056] The solid electrolyte exhibits lithium ion conductivity. Examples of the solid electrolyte include an organic solid electrolyte and an inorganic solid electrolyte.

[0057] Inorganic solid electrolytes include, for example, sulfides, oxides, nitrides, and hydrides.

[0058] The sulfide may, for example, contain Li2S and another sulfide containing at least one element selected from the group consisting of Group 13 elements, Group 14 elements, and Group 15 elements of the periodic table.

[0059] Examples of Group 13, 14 and 15 elements of the periodic table include P, Si, Ge, As, Sb and Al, preferably P, Si and Ge, and more preferably P.

[0060] Specifically, sulfides include, for example, Li2S-SiS2, Li2S-P2S5, Li2S-GeS2, Li2S-B2S3, Li2S-Ga2S3, Li2S-Al2S3, Li2S-GeS2-P2S5, Li2S-Al2S3-P2S5, Li2S-P2S3, Li2S-P2S3-P2S5, LiX-Li2S-P2S5, LiX-Li2S-SiS2, and LiX-Li2S-B2S3 (X: I, Br, or Cl).

[0061] As the solid electrolyte, preferably, an inorganic solid electrolyte is used, more preferably, a sulfide is used. The solid electrolyte can be used alone or in combination of two or more kinds. The ratio of the positive electrode active material to the solid electrolyte is not limited.

[0062] The positive electrode layer 21 has a thickness of, for example, 50 μm or more, or preferably 100 μm or more. The positive electrode layer 21 has a thickness of, for example, 500 μm or less, or preferably 300 μm or less.

[0063] (1-2) Negative electrode layer The negative electrode layer 22 is disposed away from the positive electrode layer 21 in the thickness direction of the cell 2. The negative electrode layer 22 is disposed on the opposite side of the solid electrolyte layer 23 to the positive electrode layer 21 in the thickness direction of the cell 2. The negative electrode layer 22 is in contact with the solid electrolyte layer 23 but is not in contact with the positive electrode layer 21.

[0064] The negative electrode layer 22 is made of a powder containing a negative electrode active material. The negative electrode layer 22 does not contain a resin such as a binder. In this embodiment, the negative electrode layer 22 is made of a mixture of a powder of the negative electrode active material and a powder of a solid electrolyte. The negative electrode layer 22 does not have to contain a solid electrolyte. The negative electrode layer 22 may be made of only the negative electrode active material.

[0065] The negative electrode active material is not limited as long as it is a material capable of inserting and extracting lithium ions. Examples of the negative electrode active material include carbon materials, metals and alloys thereof, semimetals, and compounds of metals or semimetals.

[0066] Examples of carbon materials include graphite (natural graphite, artificial graphite), hard carbon, and amorphous carbon. Examples of metals and their alloys include lithium and its alloys. Examples of metalloids include silicon. Examples of metal or metalloid compounds include oxides, sulfides, nitrides, hydrates, and silicides (lithium silicides) of metals or metalloids. Examples of metal or metalloid oxides include titanium oxide and silicon oxide.

[0067] The negative electrode active material may be used alone or in combination of two or more thereof. For example, silicon oxide and a carbon material may be used in combination as the negative electrode active material.

[0068] Examples of the solid electrolyte contained in the negative electrode layer 22 include the above-mentioned solid electrolytes. Preferably, the solid electrolyte contained in the negative electrode layer 22 is the same as the solid electrolyte contained in the positive electrode layer 21. The ratio of the negative electrode active material to the solid electrolyte is not limited.

[0069] The thickness of the negative electrode layer 22 is approximately the same as the thickness of the positive electrode layer 21. The thickness of the negative electrode layer 22 is, for example, 50 μm or more, or preferably 100 μm or more. The thickness of the negative electrode layer 22 is, for example, 500 μm or less, or preferably 300 μm or less.

[0070] (1-3) Solid electrolyte layer The solid electrolyte layer 23 is disposed between the positive electrode layer 21 and the negative electrode layer 22 in the thickness direction of the cell 2. The solid electrolyte layer 23 is made of a powder of a solid electrolyte. The solid electrolyte layer 23 does not contain a resin such as a binder.

[0071] The solid electrolyte may be, for example, any of the solid electrolytes described above. Preferably, the solid electrolyte is the same as the solid electrolyte contained in the positive electrode layer 21.

[0072] The solid electrolyte layer 23 is thinner than the positive electrode layer 21 and the negative electrode layer 22. The solid electrolyte layer 23 has a thickness of, for example, 10 μm or more, or preferably 30 μm or more. The solid electrolyte layer 23 has a thickness of, for example, 300 μm or less, or preferably 100 μm or less.

[0073] (2) Current collector As shown in FIG. 2B, each of the multiple current collectors 3 is stacked alternately with each of the multiple cells 2 in a stacking direction (first direction). The stacking direction is the same as the thickness direction of the cell 2. The multiple current collectors 3 include a positive electrode current collector 3A and a negative electrode current collector 3B. The positive electrode current collector 3A contacts the positive electrode layer 21 of the cell 2. The negative electrode current collector 3B contacts the negative electrode layer 22 of the cell 2.

[0074] Specifically, in this embodiment, the positive electrode current collector 3A, the first cell 2A, the negative electrode current collector 3B, and the second cell 2B are stacked in this order from one side to the other in the stacking direction. In the stacking direction, one negative electrode current collector 3B is disposed between the negative electrode layer 22 of the first cell 2A and the negative electrode layer 22 of the second cell 2B. In other words, one current collector 3 is disposed between two cells 2 in the stacking direction.

[0075] As shown in FIG. 3A and FIG. 3B, the current collector 3 has a conductor 31, an insulating member 32, and an adhesive layer 33. In other words, each of the positive electrode current collector 3A and the negative electrode current collector 3B has the conductor 31, the insulating member 32, and the adhesive layer 33. The current collector 3 also has a plurality of notches 34A, 34B, 34C, 34D, 34E, 34F, 34G, and 34H in the periphery. In other words, each of the positive electrode current collector 3A and the negative electrode current collector 3B has a plurality of notches 34A, 34B, 34C, 34D, 34E, 34F, 34G, and 34H. The number of notches is not limited.

[0076] (2-1) Conductors The conductor 31 is made of, for example, a metal and has a laminated portion 311 and a tab 312.

[0077] In the following description, the laminated portion 311 of the positive electrode current collector 3A is defined as a positive electrode laminated portion 311A, and the laminated portion 311 of the negative electrode current collector 3B is defined as a negative electrode laminated portion 311B. Also, the tab 312 of the positive electrode current collector 3A is defined as a positive electrode tab 312A, and the tab 312 of the negative electrode current collector 3B is defined as a negative electrode tab 312B. In other words, the positive electrode current collector 3A has a positive electrode laminated portion 311A ​​and a positive electrode tab 312A, and the negative electrode current collector 3B has a negative electrode laminated portion 311B and a negative electrode tab 312B.

[0078] The laminated portion 311 extends in a direction perpendicular to the lamination direction. More specifically, the laminated portion 311 extends in a first orthogonal direction and a second orthogonal direction. The first orthogonal direction and the second orthogonal direction are perpendicular to the lamination direction. The laminated portion 311 has a sheet shape. The laminated portion 311 has one side S1 and the other side S2 in the lamination direction. In other words, the conductor 31 has one side S1 and the other side S2 in the lamination direction. The laminated portion 311 is laminated on the cell 2. The laminated portion 311 contacts the cell 2. When the current collector 3 is a positive electrode current collector 3A, the positive electrode laminated portion 311A ​​is laminated on the positive electrode layer 21 of the cell 2. The positive electrode laminated portion 311A ​​contacts the positive electrode layer 21 of the cell 2. When the current collector 3 is a negative electrode current collector 3B, the negative electrode laminated portion 311B is laminated on the negative electrode layer 22 of the cell 2. The negative electrode laminated portion 311B contacts the negative electrode layer 22 of the cell 2. The laminated portion 311 has a substantially rectangular shape when viewed from the lamination direction. The laminated portion 311 has a plurality of edges E1, E2, E3, and E4.

[0079] Edge E1 is disposed at one end of stacked portion 311 in the first orthogonal direction. Edge E1 extends in the second orthogonal direction. Edge E1 has a linear shape. Edge E2 is disposed at the other end of stacked portion 311 in the first orthogonal direction. Edge E2 extends in the second orthogonal direction. Edge E2 has a linear shape. Edge E3 is disposed at one end of stacked portion 311 in the second orthogonal direction. Edge E3 extends in the first orthogonal direction. Edge E3 has a linear shape. Edge E4 is disposed at the other end of stacked portion 311 in the second orthogonal direction. Edge E4 extends in the first orthogonal direction. Edge E4 has a linear shape.

[0080] The tab 312 extends from the laminated portion 311. When the current collector 3 is a positive electrode current collector 3A, the positive electrode tab 312A extends from the positive electrode laminated portion 311A. When the current collector 3 is a negative electrode current collector 3B, the negative electrode tab 312B extends from the negative electrode laminated portion 311B.

[0081] The tab 312 is disposed on an edge of the laminated portion 311. In this embodiment, the tab 312 is disposed on one edge E3 of the laminated portion 311 in the second orthogonal direction. The tab 312 protrudes from the edge E3 of the laminated portion 311. The tab 312 is a member separate from the laminated portion 311, and may be joined to the laminated portion 311. The tab 312 has a belt shape. The tab 312 does not contact the cells 2.

[0082] When the cell 2, the positive electrode current collector 3A, and the negative electrode current collector 3B are stacked, the negative electrode tab 312B is disposed away from the positive electrode tab 312A. When the cell 2, the positive electrode current collector 3A, and the negative electrode current collector 3B are stacked, the negative electrode tab 312B does not overlap with the positive electrode tab 312A in the stacking direction.

[0083] The thickness of the conductor 31 is, for example, 1 μm or more, preferably 5 μm or more, and for example, 100 μm or less, preferably 50 μm or less.

[0084] Examples of materials for the conductor 31 include copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), indium (In), lithium (Li), tin (Sn), and alloys thereof.

[0085] (2-2) Insulating materials As shown in FIG. 3B, the insulating member 32 is laminated on one surface S1 of the conductor 31. As shown in FIG. 3A, the insulating member 32 is disposed on the laminated portion 311 of the conductor 31. The insulating member 32 is laminated on the peripheral portion of the laminated portion 311 of the conductor 31. The insulating member 32 has a substantially rectangular frame shape when viewed from the lamination direction. The insulating member 32 has a portion 32A extending along the edge E1 of the conductor 31, a portion 32B extending along the edge E2 of the conductor 31, a portion 32C extending along the edge E3 of the conductor 31, and a portion 32D extending along the edge E4 of the conductor 31. The insulating member 32 is not disposed on the tab 312 of the conductor 31.

[0086] In a state where the cell 2, the positive electrode current collector 3A, and the negative electrode current collector 3B are stacked, the insulating member 32 is disposed around the cell 2. As shown in Fig. 1B, in a state where the cell 2, the positive electrode current collector 3A, and the negative electrode current collector 3B are stacked, the insulating member 32 is disposed between the positive electrode current collector 3A and the negative electrode current collector 3B in the stacking direction. In a state where the cell 2, the positive electrode current collector 3A, and the negative electrode current collector 3B are stacked, the insulating member 32 insulates the positive electrode current collector 3A from the negative electrode current collector 3B.

[0087] In the stacking direction, the thickness of the insulating member 32 is thinner than the thickness of the cell 2. When the current collector 3 does not have the adhesive layer 33, the thickness of the insulating member 32 may be the same as the thickness of the cell 2. The thickness of the insulating member 32 is, for example, 50 μm or more, preferably 75 μm or more, and for example, 500 μm or less, preferably 400 μm or less.

[0088] Examples of materials for the insulating member 32 include polyethylene terephthalate and polyimide.

[0089] (2-3) Adhesive layer As shown in Fig. 3B, the adhesive layer 33 is laminated on the other surface S2 of the conductor 31 at the peripheral portion of the conductor 31. The current collector 3 does not need to have the adhesive layer 33. As shown in Fig. 1B, in a state in which one cell 2 is laminated between two current collectors 3, the adhesive layer 33 of the current collector 3 arranged on the other side of the cell 2 in the stacking direction is adhered to the insulating member 32 of the current collector 3 arranged on one side of the cell 2 in the stacking direction.

[0090] The sum of the thickness of the adhesive layer 33 and the thickness of the insulating member 32 is not more than the thickness of the cell 2. The thickness of the adhesive layer 33 is, for example, 30 μm or more, preferably 50 μm or more, and for example, 300 μm or less, preferably 200 μm or less.

[0091] The adhesive layer 33 is preferably insulating. Examples of the material for the adhesive layer 33 include resins such as acrylic, polyimide, and silicone, and nonwoven fabrics impregnated with these resins.

[0092] (2-4) Notch As shown in Fig. 3A, the notches 34A and 34B are disposed at one end of the current collector 3 in the first orthogonal direction. Each of the notches 34A and 34B is cut from the edge E1 of the conductor 31 to the inside of the insulating member 32. More specifically, each of the notches 34A and 34B extends from the edge E1 to the edge E2 of the conductor 31 in the first orthogonal direction. Each of the notches 34A and 34B extends to between the portion 32A and the portion 32B of the insulating member 32 in the first orthogonal direction. The insulating member 32 is interrupted at the portion where the notches 34A and 34B are formed.

[0093] The notches 34C and 34D are disposed at the other end of the current collector 3 in the first orthogonal direction. Each of the notches 34C and 34D is cut from the edge E2 of the conductor 31 to the inside of the insulating member 32. More specifically, each of the notches 34C and 34D extends from the edge E2 of the conductor 31 toward the edge E1 in the first orthogonal direction. Each of the notches 34C and 34D extends to between the portion 32A and the portion 32B of the insulating member 32 in the first orthogonal direction. The insulating member 32 is interrupted in the portion where the notches 34C and 34D are formed. The notch 34C is disposed at a distance from the notch 34A in the first orthogonal direction. The notch 34D is disposed at a distance from the notch 34B in the first orthogonal direction.

[0094] The notches 34E and 34F are disposed at one end of the current collector 3 in the second orthogonal direction. Each of the notches 34E and 34F is cut from the edge E3 of the conductor 31 to the inside of the insulating member 32. More specifically, each of the notches 34E and 34F extends from the edge E3 to the edge E4 of the conductor 31 in the second orthogonal direction. Each of the notches 34E and 34F extends in the second orthogonal direction to between the portion 32C and the portion 32D of the insulating member 32. The insulating member 32 is interrupted at the portion where the notches 34E and 34F are formed.

[0095] The notches 34G and 34H are disposed at the other end of the current collector 3 in the second orthogonal direction. Each of the notches 34G and 34H is cut from the edge E4 of the conductor 31 to the inside of the insulating member 32. More specifically, each of the notches 34G and 34H extends from the edge E4 of the conductor 31 toward the edge E3 in the second orthogonal direction. Each of the notches 34G and 34H extends to between the portion 32C and the portion 32D of the insulating member 32 in the second orthogonal direction. The insulating member 32 is interrupted at the portion where the notches 34G and 34H are formed. The notch 34G is disposed at a distance from the notch 34E in the second orthogonal direction. The notch 34H is disposed at a distance from the notch 34F in the first orthogonal direction.

[0096] When the cell 2 and the current collector 3 are stacked, the cell 2 is disposed between the notches 34A, 34B and the notches 34C, 34D in the first orthogonal direction. When the cell 2 and the current collector 3 are stacked, the cell 2 is disposed between the notches 34E, 34F and the notches 34G, 34H in the second orthogonal direction.

[0097] The shapes of the notches 34A, 34B, 34C, 34D, 34E, 34F, 34G, and 34H are not limited. Examples of the shapes of the notches 34A, 34B, 34C, 34D, 34E, 34F, 34G, and 34H include an arc shape, a triangle shape, a rectangle shape, and a trapezoid shape. The shapes of the notches 34A, 34B, 34C, 34D, 34E, 34F, 34G, and 34H may be the same or different.

[0098] (3) Positive and negative leads As shown in Fig. 1A, a portion of the positive electrode lead 4 is exposed from the exterior material 6. As shown in Fig. 4, the positive electrode lead 4 is joined to a positive electrode tab 312A inside the exterior material 6. This allows the positive electrode lead 4 to be electrically connected to the positive electrode current collector 3A. The positive electrode lead 4 is not connected to the negative electrode current collector 3B.

[0099] As shown in Fig. 1A, a portion of the negative electrode lead 5 is exposed from the exterior material 6. The negative electrode lead 5 is joined to a negative electrode tab 312B (see Fig. 3A) inside the exterior material 6. As a result, the negative electrode lead 5 is electrically connected to the negative electrode current collector 3B (see Fig. 1B). The negative electrode lead 5 is not connected to the positive electrode current collector 3A.

[0100] Each of the positive electrode lead 4 and the negative electrode lead 5 has, for example, a substantially rectangular flat plate shape. Examples of the material of the positive electrode lead 4 and the negative electrode lead 5 include pure metals and alloys. Examples of the pure metals include copper, nickel, aluminum, gold, and platinum. Examples of the alloys include alloys of the above-mentioned pure metals, stainless steel, and titanium. The positive electrode lead 4 and the negative electrode lead 5 may be plated. For example, the positive electrode lead 4 and the negative electrode lead 5 may be copper plates having a nickel plating layer and a gold plating layer.

[0101] (4) Exterior materials 1A and 1B, an exterior material 6 covers a laminate of cells 2 and current collectors 3. An example of the exterior material 6 is a metal laminate film in which resin films are laminated on both sides of a metal foil. The metal laminate film may be a draw laminate film.

[0102] 2. Manufacturing method of all-solid-state batteries Next, a method for manufacturing the all-solid-state battery 1 will be described.

[0103] The manufacturing method of the all-solid-state battery 1 includes a cell formation process (see FIGS. 5A to 6A), a pressing process (see FIG. 6B), a cutting process, a peeling process (see FIG. 6C), a lamination process (see FIGS. 7A to 9B), a positive electrode tab fixing process (see FIGS. 10A and 10B), a negative electrode tab fixing process, a positive electrode welding process (see FIG. 10C), and a negative electrode welding process.

[0104] (1) Cell formation process In the cell formation step, the cells 2 are formed on the first substrate F1 by a dry process. Specifically, the cells 2 are formed on the first substrate F1 by electrostatic screen printing.

[0105] In detail, first, a positive electrode mixture is prepared by mixing a powder of a positive electrode active material and a powder of a solid electrolyte. A negative electrode mixture is prepared by mixing a powder of a negative electrode active material and a powder of a solid electrolyte. The positive electrode mixture and the negative electrode mixture do not contain a resin such as a binder, and a liquid such as an organic solvent. The positive electrode mixture is preferably composed of a powder of a positive electrode active material and a powder of a solid electrolyte. The negative electrode mixture is preferably composed of a powder of a negative electrode active material and a powder of a solid electrolyte.

[0106] Next, as shown in FIG. 5A, the positive electrode composite material M1 is filled into the openings OP of a screen SC having a predetermined volume.

[0107] 5B, the positive electrode composite material M1 in the opening OP is pushed out toward the first substrate F1 and transferred onto the first substrate F1 by electrostatic force, thereby forming the positive electrode layer 21 on the first substrate F1.

[0108] Next, in the same manner as in the formation of the positive electrode layer 21, the solid electrolyte layer 23 is formed on the positive electrode layer 21, and the negative electrode layer 22 is formed on the solid electrolyte layer 23.

[0109] As a result, the cell 2 is formed on the first substrate F1, as shown in FIG. 6A.

[0110] The material of the first substrate F1 is not limited as long as it can be electrostatically screen printed. Examples of the material of the first substrate F1 include metal foil. Examples of the metal foil include aluminum foil.

[0111] As long as the cell 2 can be formed, the order of forming the positive electrode layer 21, the negative electrode layer 22, and the solid electrolyte layer 23 is not limited. The negative electrode layer 22 may be formed on the first substrate F1, the solid electrolyte layer 23 may be formed on the negative electrode layer 22, and the positive electrode layer 21 may be formed on the solid electrolyte layer 23.

[0112] (2) Pressing process The pressing step is performed after the cell forming step. As shown in Fig. 6B, in the pressing step, the second substrate F2 is laminated on the cell 2, and the obtained laminate L1 is pressed. Note that the obtained laminate L1 is a laminate of the first substrate F1, the cell 2, and the second substrate F2.

[0113] The material of the second substrate F2 may be the same as or different from the material of the first substrate F1.

[0114] The pressure applied to the laminate L1 is not limited as long as it can mold the cell 2. The pressure applied to the laminate L1 is, for example, 50 MPa or more, preferably 300 MPa or more, and for example, 5000 MPa or less, preferably 3000 MPa or less.

[0115] (3) Cutting process The cutting step is performed after the pressing step. In the cutting step, the cell 2 is cut into a desired shape. In this embodiment, the cell 2 is cut into a substantially rectangular shape when viewed in the thickness direction of the cell 2.

[0116] (4) Peeling process The peeling step is performed after the cutting step. The peeling step may be performed before the cutting step. In the peeling step, as shown in FIG. 6C, at least one of the first substrate F1 and the second substrate F2 is peeled off from the cell 2. In this embodiment, both the first substrate F1 and the second substrate F2 are peeled off from the cell 2. In order to prevent the cell 2 from collapsing, only one of the first substrate F1 and the second substrate F2 may be peeled off from the cell 2.

[0117] (5)Lamination process The lamination step is performed after the peeling step. That is, the method for producing an all-solid-state battery includes a cell formation step, a pressing step, and a peeling step before the lamination step.

[0118] In the stacking step, a plurality of cells 2, a plurality of positive electrode current collectors 3A, and a plurality of negative electrode current collectors 3B are stacked in the stacking direction.

[0119] Specifically, in the stacking step, first, as shown in FIG. 7A, jigs RA, RB, RE, and RF are placed in the notches 34A, 34B, 34E, and 34F of the positive electrode current collector 3A. Specifically, the jig RA is placed in the notch 34A, the jig RB is placed in the notch 34B, the jig RE is placed in the notch 34E, and the jig RF is placed in the notch 34F. Each of the jigs RA, RB, RE, and RF extends in the stacking direction. Each of the jigs RA, RB, RE, and RF is, for example, a rod. Each of the jigs RA, RB, RE, and RF has a cylindrical shape.

[0120] Next, the first cell 2A is stacked on the positive electrode collector 3A. More specifically, the first cell 2A is stacked on the conductor 31 of the positive electrode collector 3A inside the insulating member 32 of the positive electrode collector 3A (first step). As a result, with the first cell 2A stacked on the conductor 31 of the positive electrode collector 3A, the insulating member 32 of the positive electrode collector 3A is disposed around the first cell 2A. Also, with the first cell 2A stacked on the positive electrode collector 3A, the positive electrode layer 21 (see FIG. 6C) of the first cell 2A comes into contact with the conductor 31 of the positive electrode collector 3A.

[0121] Next, as shown in FIG. 7B, the first cell 2A is positioned relative to the positive electrode current collector 3A in the first orthogonal direction so that the edge E11 of the first cell 2A contacts the jigs RA and RB. The edge E11 is an edge of one end of the first cell 2A in the first orthogonal direction. More specifically, the first cell 2A is pushed toward the jigs RA and RB from the other side in the first orthogonal direction by the jigs RC and RD. At this time, the jig RC enters the notch 34C, and the jig RD enters the notch 34D. By the edge E11 contacting the jigs RA and RB, the first cell 2A is positioned relative to the positive electrode current collector 3A in the first orthogonal direction.

[0122] Next, as shown in FIG. 8A, the first cell 2A is positioned relative to the positive electrode current collector 3A in the second orthogonal direction so that the edge E12 of the first cell 2A contacts the jigs RE and RF. The edge E12 is an edge of one end of the first cell 2A in the second orthogonal direction. More specifically, the first cell 2A is pushed toward the jigs RE and RF from the other side in the second orthogonal direction by the jigs RG and RH. At this time, the jig RG enters the notch 34G, and the jig RH enters the notch 34H. By the edge E12 contacting the jigs RE and RF, the first cell 2A is positioned relative to the positive electrode current collector 3A in the second orthogonal direction.

[0123] Next, as shown in Fig. 8B, the negative electrode current collector 3B is laminated on the negative electrode layer 22 of the first cell 2A (second step), and the jigs RA, RB, RE, and RF are placed in the notches 34A, 34B, 34E, and 34F of the negative electrode current collector 3B. With the negative electrode current collector 3B laminated on the first cell 2A, the conductor 31 of the negative electrode current collector 3B comes into contact with the negative electrode layer 22 (see Fig. 6C) of the first cell 2A.

[0124] Next, the second cell 2B is stacked on the negative electrode current collector 3B (third step). More specifically, the second cell 2B is stacked on the conductor 31 of the negative electrode current collector 3B inside the insulating member 32 of the negative electrode current collector 3B. With the second cell 2B stacked on the negative electrode current collector 3B, the negative electrode layer 22 of the second cell 2B contacts the conductor 31 of the negative electrode current collector 3B. In other words, when the negative electrode layer 22 of the first cell 2A is in contact with the current collector 3 (negative electrode current collector 3B), the second cell 2B is stacked on the negative electrode current collector 3B so that the negative electrode layer 22 of the second cell 2B contacts the negative electrode current collector 3B.

[0125] In this manner, in the stacking step, the cells 2 and the current collectors 3 are stacked alternately so that one current collector 3 is disposed between two cells 2.

[0126] Next, as shown in Figures 9A and 9B, the second cell 2B is positioned relative to the negative electrode current collector 3B in the first orthogonal direction so that the edge E11 of the second cell 2B contacts the jigs RA and RB (see Figure 9A), and the second cell 2B is positioned relative to the negative electrode current collector 3B in the second orthogonal direction so that the edge E12 of the second cell 2B contacts the jigs RE and RF (see Figure 9B).

[0127] In this way, each time a cell 2 is stacked on a current collector 3, the cell 2 is positioned relative to the current collector 3 in the first orthogonal direction so that the edge E11 of the cell 2 contacts the jigs RA and RB, and the cell 2 is positioned relative to the current collector 3 in the second orthogonal direction so that the edge E12 of the cell 2 contacts the jigs RE and RF.

[0128] The stacking process is completed by stacking the desired number of cells 2 and current collectors 3.

[0129] (5) Positive electrode tab fixing process and negative electrode tab fixing process The positive electrode tab fixing step and the negative electrode tab fixing step are performed after the lamination step.

[0130] In the positive electrode tab fixing step, all the positive electrode tabs 312A are fixed to the laminate L2 of the cells 2, the positive electrode laminate portion 311A, and the negative electrode laminate portion 311B.

[0131] 10A, in the positive electrode tab fixing step, first, at least one positive electrode tab 312A is bent to form a positive electrode first portion 3121A, a positive electrode second portion 3122A, and a positive electrode bent portion 3123A in each of all the positive electrode tabs 312A. In this embodiment, all the positive electrode tabs 312A are bent except for the positive electrode tab 312A located at the most one side (bottom) in the stacking direction. In other words, when the positive electrode lead 4 is located at one end (bottom) of the all-solid-state battery 1 in the stacking direction, the unbent positive electrode tab 312A is located at the most one side (place going straight toward the positive electrode lead 4) in the stacking direction.

[0132] In addition, in other embodiments, depending on the position of the positive electrode lead 4, the positive electrode tab 312A that is not bent may not be located at the most one side (bottom) in the stacking direction. For example, when the positive electrode lead 4 is located in the center of the all-solid-state battery 1 in the stacking direction, all the positive electrode tabs 312A may be folded (i.e., without folding) except for the positive electrode tab 312A located in the center of the stacking direction. In other words, when the positive electrode lead 4 is located in the center of the all-solid-state battery 1 in the stacking direction, the positive electrode tab 312A that is not bent may be located in the center of the stacking direction (a place that goes straight toward the positive electrode lead 4).

[0133] The positive electrode first portion 3121A extends from the positive electrode laminate 311A. The positive electrode first portion 3121A is disposed on a side of the laminate L2 in a direction perpendicular to the stacking direction. In this embodiment, the positive electrode first portion 3121A is disposed on one side of the laminate L2 in a second perpendicular direction. The positive electrode first portion 3121A extends in the stacking direction (first direction) along the side surface of the laminate L2.

[0134] The positive electrode second portion 3122A is disposed on the opposite side of the laminate L2 to the positive electrode first portion 3121A in the second orthogonal direction. The positive electrode second portion 3122A extends in a direction away from the laminate L2. The direction in which the positive electrode second portion 3122A extends is defined as the second direction. In this embodiment, the positive electrode second portion 3122A extends in the second orthogonal direction. That is, in this embodiment, the second direction is the same direction as the second orthogonal direction.

[0135] Positive electrode bent portion 3123A connects positive electrode first portion 3121A and positive electrode second portion 3122A. Positive electrode bent portion 3123A bends from positive electrode first portion 3121A toward positive electrode second portion 3122A.

[0136] 10B, all of the positive electrode first portions 3121A are fixed to the laminate L2 such that all of the positive electrode second portions 3122A are overlapped with one another. The method for fixing all of the positive electrode first portions 3121A to the laminate L2 is not limited. For example, all of the positive electrode first portions 3121A may be fixed to the laminate L2 by a fixing member 100.

[0137] The shape of the fixing member 100 is not limited. In this embodiment, the fixing member 100 has a recess 100A. The recess 100A can accommodate the laminate L2. The recess 100A has a box shape. When the fixing member 100 has the recess 100A, the fixing member 100 may be placed over the laminate L2, and all the positive electrode first portions 3121A may be fixed to the laminate L2 by the inner surface of the recess 100A. In detail, the inner surface of the recess 100A presses the bundle of the positive electrode first portions 3121A toward the other side of the second orthogonal direction so as to approach the laminate L2. When the exterior material 6 of the all-solid-state battery 1 is a squeeze laminate film, the fixing member 100 having the recess 100A may be the exterior material 6 of the all-solid-state battery 1.

[0138] In the negative electrode tab fixing step, all the negative electrode tabs 312B are fixed to the laminate L2. The negative electrode tab fixing step can be explained in the same manner as the positive electrode tab fixing step. Therefore, illustrations are omitted in the explanation.

[0139] In the negative electrode tab fixing step, similarly to the positive electrode tab fixing step, first, at least one negative electrode tab 312B is bent to form a negative electrode first portion 3121B, a negative electrode second portion 3122B, and a negative electrode bent portion 3123B in each of all the negative electrode tabs 312B. In the negative electrode tab fixing step, similarly to the positive electrode tab fixing step, all the negative electrode tabs 312B are bent except for the negative electrode tab 312B located on the most one side (bottom) in the stacking direction. In other words, when the negative electrode lead 5 is located at one end (bottom) of the all-solid-state battery 1 in the stacking direction, the unbent negative electrode tab 312B is located on the most one side (place going straight toward the negative electrode lead 5) in the stacking direction.

[0140] Similarly to the unfolded positive electrode tab 312A, the unfolded negative electrode tab 312B may not be located at the most one side (bottom) in the stacking direction depending on the position of the negative electrode lead 5. For example, when the negative electrode lead 5 is located in the center of the all-solid-state battery 1 in the stacking direction, the unfolded negative electrode tab 312B may be located in the center in the stacking direction (a place going straight toward the negative electrode lead 5).

[0141] The negative electrode first portion 3121B extends from the negative electrode laminate 311B. The negative electrode first portion 3121B is disposed on a side of the laminate L2 in a direction perpendicular to the stacking direction. In this embodiment, the negative electrode first portion 3121B is disposed on one side of the laminate L2 in a second perpendicular direction. The negative electrode first portion 3121B is disposed away from the positive electrode first portion 3121A in the first perpendicular direction. The negative electrode first portion 3121B extends in the stacking direction (first direction) along the side surface of the laminate L2.

[0142] The negative electrode second portion 3122B is disposed on the opposite side of the laminate L2 to the negative electrode first portion 3121B in the second orthogonal direction. The negative electrode second portion 3122B is disposed away from the positive electrode second portion 3122A in the first orthogonal direction. The negative electrode second portion 3122B extends in a direction away from the laminate L2. The direction in which the negative electrode second portion 3122B extends is defined as a third direction. The negative electrode second portion 3122B may extend in the same direction as the positive electrode second portion 3122A, or may extend in a direction different from that of the positive electrode second portion 3122A. When the negative electrode second portion 3122B extends in the same direction as the positive electrode second portion 3122A, the third direction is the same as the second direction. When the negative electrode second portion 3122B extends in a direction different from that of the positive electrode second portion 3122A, the third direction is a direction different from the second direction. In this embodiment, the negative electrode second portion 3122B extends in the second orthogonal direction. That is, in this embodiment, the third direction is the same as the second direction and the second orthogonal direction.

[0143] The negative electrode bent portion 3123B connects the negative electrode first portion 3121B and the negative electrode second portion 3122B. The negative electrode bent portion 3123B bends from the negative electrode first portion 3121B toward the negative electrode second portion 3122B.

[0144] Next, in the negative electrode tab fixing step, similarly to the positive electrode tab fixing step, all the negative electrode first portions 3121B are fixed to the laminate L2 so that all the negative electrode second portions 3122B are overlapped together. In the negative electrode tab fixing step, all the negative electrode first portions 3121B may be fixed to the laminate L2 by the fixing member 100. When the fixing member 100 has a recess 100A, the fixing member 100 may be placed over the laminate L2, and all the negative electrode first portions 3121B may be fixed to the laminate L2 by the inner surface of the recess 100A.

[0145] In this embodiment, the fixing member 100 is placed over the laminate L2, and all of the positive electrode first portions 3121A and all of the negative electrode first portions 3121B are fixed to the laminate L2 by the inner surface of the recess 100A. As a result, the positive electrode tab fixing step and the negative electrode tab fixing step are performed simultaneously.

[0146] The positive electrode tab fixing step and the negative electrode tab fixing step do not have to be performed simultaneously. The negative electrode tab fixing step may be performed after the positive electrode tab fixing step, or the positive electrode tab fixing step may be performed after the negative electrode tab fixing step.

[0147] (6) Positive electrode welding process and negative electrode welding process The positive electrode welding step is performed after the positive electrode tab fixing step, and the negative electrode welding step is performed after the negative electrode tab fixing step.

[0148] 10C, in the positive electrode welding step, with all the positive electrode first portions 3121A fixed to the laminate L2, all the positive electrode second portions 3122A and the positive electrode tabs 312A located on the furthest side in the stacking direction (the unbent positive electrode tabs 312A that go straight toward the positive electrode lead 4) are ultrasonically welded to the positive electrode lead 4. In other words, with all the positive electrode first portions 3121A fixed to the laminate L2, a bundle of all the positive electrode second portions 3122A and the unbent positive electrode tabs 312A is ultrasonically welded to the positive electrode lead 4. As a result, all the positive electrode tabs 312A are joined to the positive electrode lead 4.

[0149] At this time, horn H of the ultrasonic welding device moves away from positive electrode bent portion 3123A and comes into contact with the bundle of positive electrode second portion 3122A. That is, in the positive electrode welding step, horn H of the ultrasonic welding device does not come into contact with positive electrode bent portion 3123A but comes into contact with positive electrode second portion 3122A.

[0150] The negative electrode welding step can be explained in the same manner as the positive electrode welding step, and therefore, illustrations thereof will be omitted.

[0151] In the negative electrode welding step, all the negative electrode second portions 3122B and the negative electrode tabs 312B located on the furthest side in the stacking direction (the unbent negative electrode tabs 312B that go straight toward the negative electrode lead 5) are ultrasonically welded to the negative electrode lead 5 (see FIG. 1A) with all the negative electrode first portions 3121B fixed to the laminate L2. In other words, with all the negative electrode first portions 3121B fixed to the laminate L2, a bundle of all the negative electrode second portions 3122B and the unbent negative electrode tabs 312B is ultrasonically welded to the negative electrode lead 5. As a result, all the negative electrode tabs 312B are joined to the negative electrode lead 5.

[0152] At this time, horn H of the ultrasonic welding device moves away from negative electrode bent portion 3123B and comes into contact with the bundle of negative electrode second portion 3122B. That is, in the negative electrode welding process, horn H of the ultrasonic welding device does not come into contact with negative electrode bent portion 3123B but comes into contact with negative electrode second portion 3122B.

[0153] In this embodiment, the positive electrode welding process and the negative electrode welding process are performed with fixing member 100 covering laminate L2. Therefore, fixing member 100 can prevent horn H of the ultrasonic welding device from coming into contact with positive electrode bending portion 3123A in the positive electrode welding process, and can prevent horn H of the ultrasonic welding device from coming into contact with negative electrode bending portion 3123B in the negative electrode welding process. As a result, damage to positive electrode bending portion 3123A and negative electrode bending portion 3123B due to contact with horn H of the ultrasonic welding device can be prevented.

[0154] After the positive electrode welding step and the negative electrode welding step, the laminate L2 is vacuum-packed in an exterior material 6.

[0155] This completes the production of the above-mentioned all-solid-state battery 1 (see FIG. 1A).

[0156] 3. Effects (1) According to the manufacturing method of the all-solid-state battery 1, as shown in FIG. 10A, before ultrasonic welding of the positive electrode tab 312A and the positive electrode lead 4, the positive electrode tab 312A is bent to form the positive electrode first portion 3121A, the positive electrode second portion 3122A, and the positive electrode bent portion 3123A. The positive electrode first portion 3121A extends in the stacking direction (first direction) of the multiple cells 2 along the side surface of the laminate L2 in which the multiple cells 2 are stacked. The positive electrode second portion 3122A extends in a direction (second direction) away from the laminate L2. The positive electrode bent portion 3123A connects the positive electrode first portion 3121A and the positive electrode second portion 3122A.

[0157] Then, as shown in FIG. 10C, in a positive electrode welding step, positive electrode second portion 3122A is ultrasonically welded to positive electrode lead 4 in a state in which positive electrode first portion 3121A is fixed to laminate L2.

[0158] By fixing the positive electrode first portion 3121A to the laminate L2, restoration of the positive electrode tab 312A in the positive electrode welding step is suppressed. Therefore, there is no need to hold the positive electrode tab 312A attempting to restore with the horn H of the ultrasonic welding device.

[0159] Therefore, damage to the positive electrode tab 312A by the edge of the horn H can be suppressed.

[0160] As a result, it is possible to prevent the positive electrode tab 312A from being damaged when ultrasonically welding the positive electrode tab 312A to the positive electrode lead 4. The same applies when ultrasonically welding the negative electrode tab 312B (see FIG. 3A) to the negative electrode lead 5 (see FIG. 1A).

[0161] (2) According to the manufacturing method of the all-solid-state battery 1, as shown in FIG. 10B, a fixing member 100 having a recess 100A capable of accommodating the laminate L2 is placed over the laminate L2, and all of the positive electrode first portions 3121A and all of the negative electrode first portions 3121B are fixed to the laminate L2 by the inner surface of the recess 100A.

[0162] Therefore, the positive electrode first portion 3121A and the negative electrode first portion 3121B can be fixed to the laminate L2 by the simple method of covering the laminate L2 with the fixing member 100 having the recess 100A.

[0163] As a result, the all-solid-state battery 1 can be efficiently manufactured while the fixing member 100 protects the laminate L2.

[0164] (3) According to the manufacturing method of the all-solid-state battery 1, as shown in FIG. 10B, the exterior material 6 of the all-solid-state battery 1 can be used as the fixing member 100.

[0165] Therefore, the laminate L2 can be handled in a state in which it is placed in the exterior packaging material 6, and further, after the positive electrode welding step and the negative electrode welding step, the laminate L2 can be packed using the exterior packaging material 6 used as the fixing member 100.

[0166] As a result, the all-solid-state battery 1 can be manufactured efficiently.

[0167] (4) According to the manufacturing method of all-solid-state battery 1, in the positive electrode welding step, horn H of the ultrasonic welding device does not contact positive electrode bent portion 3123A but contacts positive electrode second portion 3122A, as shown in Fig. 10C. Similarly, in the negative electrode welding step, horn H of the ultrasonic welding device does not contact negative electrode bent portion 3123B but contacts negative electrode second portion 3122B.

[0168] Therefore, damage to the positive electrode tab 312A and the negative electrode tab 312B by the edge of the horn H can be suppressed.

[0169] (5) According to the method for producing the all-solid-state battery 1, the cell 2 formed on the first substrate F1 by a dry process is pressed and solidified, and then the cell 2 is laminated on the current collector 3.

[0170] 5A to 6A, the positive electrode layer 21, the solid electrolyte layer 23, and the negative electrode layer 22 are formed in this order on the first substrate F1 by electrostatic screen printing. In this way, the cell 2 is formed on the first substrate F1 by a dry process (cell formation process).

[0171] 6B, a second base material F2 is laminated on the cell 2, and the resulting laminate L1 is pressed, thereby solidifying the cell 2 (pressing step).

[0172] Next, as shown in FIG. 6C, at least one of the first substrate F1 and the second substrate F2 is peeled off from the cell 2 (peeling step).

[0173] Thereafter, as shown in FIG. 1B, the cells 2 and the current collectors 3 are laminated (lamination step).

[0174] This makes it possible to manufacture an all-solid-state battery 1 having a cell 2 manufactured by a dry method.

[0175] Therefore, in the obtained all-solid-state battery 1, compared to an all-solid-state battery having a cell manufactured by a wet method, the decrease in power generation efficiency caused by voids generated in the cell when the solvent evaporates and resins such as binders is suppressed.

[0176] As a result, the method for manufacturing the all-solid-state battery 1 can improve the energy density of the manufactured all-solid-state battery 1.

[0177] (6) According to the manufacturing method of the all-solid-state battery 1, the lamination process includes a first step of laminating a first cell 2A on a positive electrode current collector 3A as shown in FIG. 7A, a second step of laminating a negative electrode current collector 3B on the first cell 2A as shown in FIG. 8B, and a third step of laminating a second cell 2B on the negative electrode current collector 3B.

[0178] In FIG. 8B, the second cell 2B is stacked on top of the negative electrode current collector 3B, i.e., the second cell 2B is stacked on top of the current collector 3 which is in contact with the negative electrode layer 22 of the first cell 2A, so that the second cell 2B is stacked on top of the negative electrode current collector 3B such that the negative electrode layer 22 of the second cell 2B is in contact with the negative electrode current collector 3B.

[0179] In this way, a bi-cell type all-solid-state battery 1 in which the first cell 2A and the second cell 2B are in contact with one current collector 3 can be manufactured.

[0180] (7) According to the method for producing the all-solid-state battery 1, as shown in Figures 3A and 3B, the current collector 3 has a conductor 31 and an insulating member 32 laminated on the periphery of the conductor 31. As shown in Figure 8A, in the lamination step, the cell 2 is laminated on the conductor 31, and the insulating member 32 is disposed around the cell 2.

[0181] Since a current collector 3 having an insulating member 32 laminated around the periphery of a conductor 31 is used, the all-solid-state battery 1 can be manufactured through a simple process of laminating the cell 2, the positive electrode current collector 3A, and the negative electrode current collector 3B.

[0182] (8) According to the manufacturing method of the all-solid-state battery 1, as shown in FIG. 3B, the insulating member 32 is laminated on one surface S1 of the conductor 31, and the current collector 3 has an adhesive layer 33 laminated on the other surface S2 of the conductor 31.

[0183] Therefore, for example, when a cell 2 is stacked on a positive electrode current collector 3A and then a negative electrode current collector 3B is stacked on the cell 2, the adhesive layer 33 of the negative electrode current collector 3B can be adhered to the insulating member 32 of the positive electrode current collector 3A.

[0184] This makes it possible to prevent a short circuit between the positive electrode current collector 3A and the negative electrode current collector 3B.

[0185] (9) According to the manufacturing method of the all-solid-state battery 1, as shown in FIG. 3A , the current collector 3 has notches 34A and 34B cut from the edge E1 of the conductor 31 to the inside of the insulating member 32, and notches 34E and 34F cut from the edge E3 of the conductor 31 to the inside of the insulating member 32.

[0186] Then, in the stacking process, as shown in Figures 7A and 7B, a jig RA is placed in the notch 34A, and a jig RB is placed in the notch 34B, and the cell 2 is positioned relative to the positive electrode collector 3A in the first direction so that the edge E11 of the cell 2 contacts the jigs RA and RB.

[0187] Also, as shown in Figures 7B and 8A, a jig RE is placed in the notch 34E, and a jig RF is placed in the notch 34F, and the cell 2 is positioned relative to the positive electrode collector 3A in the second direction so that the edge E12 of the cell 2 contacts the jigs RE and RF.

[0188] As shown in Figs. 8B to 9B, the cell 2 is positioned in the same manner with respect to the negative electrode current collector 3B.

[0189] This makes it possible to easily stack the cell 2, the positive electrode current collector 3A, and the negative electrode current collector 3B while preventing the position of the cell 2 from being shifted relative to the positive electrode current collector 3A and the negative electrode current collector 3B.

[0190] 4. Variations In the following, modified examples will be described. In the modified examples, the same members as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0191] In the above-described embodiment, the fixing member 100 having the recess 100A is used in the positive electrode tab fixing step and the negative electrode tab fixing step. In this regard, in the positive electrode tab fixing step, all the positive electrode first portions 3121A may be fixed to the laminate L2 with an adhesive tape. Also, in the negative electrode tab fixing step, all the negative electrode first portions 3121B may be fixed to the laminate L2 with an adhesive tape. [Explanation of symbols]

[0192] 1 All-solid-state battery 2 Cell 21 Positive electrode layer 22 Negative electrode layer 23 Solid electrolyte layer 2A 1st cell 2B Second cell 3A positive electrode current collector 31 Conductors 32 Insulating materials 33 Adhesive layer 311A Positive electrode laminate 312A Positive Tab 3121A Positive electrode 1st section 3122A Positive electrode 2nd part 3123A Positive electrode bending part 3B Negative electrode current collector 311B Negative electrode laminate 312B Negative tab 3121B Negative electrode 1st part 3122B Negative electrode 2nd part 3123B Negative electrode bending part 4 Positive Lead 5 Negative lead 6 Exterior materials 100 Fixing member 100A Recess F1 1st base material F2 2nd base material H Horn L1 laminate L2 laminate RA~RH Jig S1 One side S2 Other side

Claims

1. a stacking step of stacking, in the first direction, a plurality of cells each having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer in a first direction, a plurality of positive electrode current collectors each having a positive electrode laminate portion stacked on the positive electrode layer of the cell and a positive electrode tab extending from the positive electrode laminate portion, and a plurality of negative electrode current collectors each having a negative electrode laminate portion stacked on the negative electrode layer of the cell and a negative electrode tab extending from the negative electrode laminate portion; a positive electrode tab fixing step of bending at least one of the positive electrode tabs to form a positive electrode first portion extending in the first direction along a side surface of a stack of the cell, the positive electrode laminated portion, and the negative electrode laminated portion, a positive electrode second portion extending in a second direction away from the stack, and a positive electrode bent portion connecting the positive electrode first portion and the positive electrode second portion, and fixing all of the positive electrode first portions to the stack; a negative electrode tab fixing process of bending at least one of the negative electrode tabs to form a negative electrode first portion extending in the first direction along a side surface of the laminate, a negative electrode second portion extending in a third direction away from the laminate, and a negative electrode bent portion connecting the negative electrode first portion and the negative electrode second portion, and fixing all of the negative electrode first portions to the laminate; a positive electrode welding step of ultrasonically welding all of the positive electrode second portions to a positive electrode lead in a state in which all of the positive electrode first portions are fixed to the laminate; a negative electrode welding process of ultrasonically welding all of the negative electrode second portions to a negative electrode lead in a state in which all of the negative electrode first portions are fixed to the laminate; A method for producing an all-solid-state battery, comprising:

2. the positive electrode tab fixing step and the negative electrode tab fixing step are performed by covering the stack with a fixing member having a recess capable of accommodating the stack, and fixing all of the positive electrode first portions and all of the negative electrode first portions to the stack by an inner surface of the recess, The method for producing an all-solid-state battery according to claim 1 , wherein the positive electrode welding step and the negative electrode welding step are performed in a state in which the fixing member is placed over the laminate.

3. The method for producing an all-solid-state battery according to claim 2 , wherein the fixing member is an exterior material of the all-solid-state battery.

4. In the positive electrode tab fixing step, all of the positive electrode first portions are fixed to the laminate with an adhesive tape, The method for producing an all-solid-state battery according to claim 1 , wherein in the negative electrode tab fixing step, all of the negative electrode first portions are fixed to the laminate with an adhesive tape.

5. In the positive electrode welding step, a horn of an ultrasonic welding device does not contact the positive electrode bent portion but contacts the positive electrode second portion, 2. The method for producing an all-solid-state battery according to claim 1, wherein in the negative electrode welding step, a horn of an ultrasonic welding device does not come into contact with the negative electrode bent portion but comes into contact with the negative electrode second portion.

6. The positive electrode layer is made of a powder containing a positive electrode active material, The negative electrode layer is made of a powder containing a negative electrode active material, the solid electrolyte layer is made of a powder of a solid electrolyte; In the method for producing an all-solid-state battery, before the lamination step, A cell forming step of forming the cells on a first substrate by a dry process; a pressing step of laminating a second substrate on the cells and pressing the resulting laminate; a peeling step of peeling off at least one of the first substrate and the second substrate from the cell; The method for producing an all-solid-state battery according to claim 1 , further comprising:

7. The lamination step includes: a first step of stacking a first cell on the positive electrode current collector such that the positive electrode layer of the first cell is in contact with the positive electrode current collector; Following the first step, a second step of laminating the negative electrode current collector on the negative electrode layer of the first cell; a third step of stacking a second cell on the negative electrode current collector such that the negative electrode layer of the second cell is in contact with the negative electrode current collector; The method for producing the all-solid-state battery according to claim 1 ,

8. The positive electrode current collector and the negative electrode current collector are Conductor and an insulating member laminated on a peripheral edge of the conductor; having The method for producing an all-solid-state battery according to claim 1 , wherein in the stacking step, the cells are stacked on the conductor.

9. the insulating member is laminated on one surface of the conductor, The positive electrode current collector and the negative electrode current collector are The method for producing an all-solid-state battery according to claim 8 , further comprising: an adhesive layer laminated on the other surface of the conductor in a peripheral portion of the conductor.

10. the positive electrode current collector and the negative electrode current collector each have a notch cut from an edge of the conductor to an inside of the insulating member, 9. The method for producing an all-solid-state battery according to claim 8, wherein in the stacking step, a jig is placed in the notch, and the cell is positioned with respect to the positive electrode current collector or the negative electrode current collector so that an edge of the cell contacts the jig.

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