Method for producing all solid state battery

Abstract

A method for producing an all solid state battery 1 comprises: a laminating step for laminating a plurality of cells 2, a plurality of positive electrode current collectors 3A, and a plurality of negative electrode current collectors 3B; a positive electrode tab fixing step for bending positive electrode tabs 312A to form positive electrode first parts 3121A which extend along a side surface of a laminated body L2, positive electrode second parts 3122A which extend in a direction away from the laminated body L2, and positive electrode bent parts 3123A and fixing all the positive electrode first parts 3121A to the laminated body L2; and a positive electrode welding step for welding, with ultrasonic waves, all the positive electrode second parts 3122A to a positive electrode lead 4 in a state in which all the positive electrode first parts 3121A are fixed to the laminated body L2.

Description

Manufacturing method for all-solid-state batteries

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

[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 disposed between the positive electrode plate and the negative electrode plate are stacked, and 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 listed below).

[0003] In the manufacturing method of the above-mentioned stacked battery, when joining multiple positive electrode current collector leads to a positive electrode current collector terminal, the multiple positive electrode current collector leads are converged to one side in the stacking direction of the stacked electrode body using a converging head, and then the tips of the converged multiple positive electrode current collector leads are ultrasonically welded to the positive electrode current collector terminal.

[0004] JP 2012-164470 A

[0005] In the manufacture of a stacked battery such as that described in Patent Document 1, for example, when it is desired to prevent the stacked battery from becoming too large, the positive electrode current collector lead and the positive electrode current collector terminal may be 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] Therefore, 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 ultrasonic welding is performed while pressing the positive electrode current collector lead to be restored with an ultrasonic horn, the portion of the positive electrode current collector lead that is being pressed 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 prevent breakage of a tab extending from a current collector when ultrasonically welding the tab and a lead.

[0010] The present invention [1] provides a method for manufacturing a battery, comprising: a lamination step 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 laminate portion laminated 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 laminated on the negative electrode layer of the cell and a negative electrode tab extending from the negative electrode laminate 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 laminate portion, and the negative electrode laminate 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; a 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 bending 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 in a state where all of the positive electrode first portions are 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 in a state where all of the negative electrode first portions are fixed to the laminate.

[0011] According to this method, before ultrasonically 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 the side of the stack in which the 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 the positive electrode welding step, the positive electrode second portion is ultrasonically welded to the positive electrode lead while 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 during the positive electrode welding step is suppressed, and therefore it is not necessary to hold the restoring positive electrode tab with the horn of the ultrasonic welding device.

[0014] Therefore, it is possible to prevent the positive electrode tab from being damaged by the edge of the horn.

[0015] As a result, when ultrasonically welding the positive electrode tab and the positive electrode lead together, damage to the positive electrode tab can be suppressed. The same applies when ultrasonically welding the negative electrode tab and the negative electrode lead together.

[0016] The present invention [2] includes the method for manufacturing an all-solid-state battery according to 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 inner surfaces of the recess, and the positive electrode welding step and the negative electrode welding step are performed in a state in which the stack is covered with the fixing member.

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

[0018] As a result, the all-solid-state battery can be efficiently manufactured while protecting the stack with the fixing member.

[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 a fixing member.

[0021] Therefore, the stack can be handled while it is enclosed in the exterior packaging material, and further, after the positive electrode welding step and the negative electrode welding step, the stack can be packed 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 manufacturing 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] This method can prevent the positive electrode tab and the negative electrode tab from being damaged by the edge of the horn.

[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 dry-forming the cell on a first substrate, a pressing step of laminating a second substrate on the cell and pressing the obtained laminate, and a peeling step of peeling 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 all-solid-state batteries having cells manufactured by a wet method, the obtained all-solid-state battery suppresses the voids that occur in the cell when the solvent evaporates and the decrease in power generation efficiency caused 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, subsequent to 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, subsequent to 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 edge of the conductor, and in the laminating 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 edge 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], wherein the insulating member is laminated on one surface of the conductor, and the positive electrode current collector and the negative electrode current collector further have an adhesive layer laminated on the other surface of the conductor at the periphery of the conductor.

[0036] According to this method, for example, when a cell is stacked on a positive electrode current collector and 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 can prevent short circuits 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 out from an edge of the conductor to an 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 this method, the cells, positive electrode current collectors, and negative electrode current collectors can be easily stacked while preventing the position of the cells from shifting relative to the positive electrode current collectors or negative electrode current collectors.

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

[0041] FIG. 1A is a plan view of an all-solid-state battery according to one embodiment of the present invention. FIG. 1B is an A-A cross-sectional view of the all-solid-state battery shown in FIG. 1A. FIG. 2A is a cross-sectional view showing the layer structure of the cell shown in FIG. 1B. FIG. 2B is an enlarged view of the all-solid-state battery shown in FIG. 1B. FIG. 3A is a plan view of the positive electrode current collector shown in FIG. 2B. FIG. 3B is a B-B cross-sectional view of the positive electrode current collector shown in FIG. 3A. FIG. 4 is a C-C cross-sectional view of the all-solid-state battery shown in FIG. 1A. FIGS. 5A and 5B are process diagrams illustrating a method for manufacturing an all-solid-state battery. FIG. 5A shows a state in which the openings of the screen are filled with a positive electrode mixture in the cell formation process. FIG. 5B shows a state in which the positive electrode mixture in the openings is transferred onto a first substrate to form a positive electrode layer on the first substrate in the cell formation process. FIGS. 6A to 6C are process diagrams illustrating a method for manufacturing 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 step. FIG. 6B shows a pressing step. FIG. 6C shows a peeling step. FIGS. 7A and 7B are process diagrams illustrating a method for manufacturing an all-solid-state battery, following FIG. 6C. FIG. 7A shows a state in which a first cell is stacked on a positive electrode current collector in a stacking step. FIG. 7B shows a state in which the first cell is positioned relative to the positive electrode current collector in a first orthogonal direction in a stacking step. FIGS. 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 the first cell is positioned relative to the 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. FIGS. 9A and 9B are process diagrams illustrating a method for manufacturing an 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. Figs. 10A to 10C are process diagrams illustrating the method for manufacturing an 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 process.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.

[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 in 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. Furthermore, the cell 2 may have a substantially circular shape when viewed in 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, cell 2 has a positive electrode layer 21, a negative electrode layer 22, and a solid electrolyte layer 23. Cell 2 is a bare cell. Cell 2 is composed of positive electrode layer 21, a negative electrode layer 22, and a solid electrolyte layer 23. Cell 2 does not have a current collector.

[0047] (1-1) Positive Electrode Layer The positive electrode layer 21 is disposed apart 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 solid electrolyte layer 23 from the negative electrode layer 22 in the first direction. The positive electrode layer 21 is in contact with the solid electrolyte layer 23 but 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 necessarily have to contain the 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. Examples of the lithium-containing oxide include lithium-nickel composite oxide (LiNi Ｘ M １－Ｘ O ２ ), lithium cobalt oxide (LiCoO ２ ), lithium nickel oxide (LiNiO ２ ), lithium nickel cobalt aluminum composite oxide (LiNi ０．８ Co ０．１５ Al ０．０５ O ２ , NCA-based layered oxide), lithium manganese oxide (spinel-type lithium manganese oxide (LiMn ２ O ４ )), Li-excess composite oxide (Li ２ MnO ３ -LiMO ２ ) are listed.

[0050] The positive electrode active material is not limited to a lithium-containing oxide as long as it is capable of inserting and extracting lithium ions. Examples of the positive electrode active material include olivine-based compounds (LiMPO ４ ) and sulfur-containing compounds (Li ２ S) can be mentioned.

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

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

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

[0054] As the coating material, for example, Li ４ Ti ５ O １２ , LiTaO ３ , Li ４ NbO ３ , LiAlO ２ , Li ２ ZrO ３ , Li ２ WO ４ , Li２ TiO ３ , Li ２ B ４ O ７ , Li ３ P.O. ４ , Li ２ MoO ４ , LiBO ２ , alumina (Al ２ O ３ ), 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 organic solid electrolytes and inorganic solid electrolytes.

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

[0058] Examples of sulfides include Li ２ Examples of the sulfide include those containing S and other sulfides 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 elements, Group 14 elements, and Group 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, the sulfide may be, for example, Li ２ S-SiS ２ , Li ２ S-P ２ S ５ , Li ２ S-GeS ２ , Li ２ S-B ２ S ３ , Li ２ S-Ga ２ S ３ , Li ２ S-Al ２ S ３ , Li ２ S-GeS２ -P ２ S ５ , Li ２ S-Al ２ S ３ -P ２ S ５ , Li ２ S-P ２ S ３ , Li ２ S-P ２ S ３ -P ２ S ５ , LiX-Li ２ S-P ２ S ５ , LiX-Li ２ S-SiS ２ , and LiX-Li ２ S-B ２ S ３ (X: I, Br or Cl).

[0061] The solid electrolyte is preferably an inorganic solid electrolyte, more preferably a sulfide. The solid electrolyte may be used alone or in combination of two or more. 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 from 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 necessarily have to contain the 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, and 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 can be used alone or in combination of two or more thereof. For example, silicon oxide and a carbon material can be used in combination as the negative electrode active material.

[0068] Examples of the solid electrolyte contained in the anode layer 22 include the solid electrolytes described above. Preferably, the solid electrolyte contained in the anode layer 22 is the same as the solid electrolyte contained in the cathode layer 21. The ratio of the anode 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 solid electrolyte powder. The solid electrolyte layer 23 does not contain a resin such as a binder.

[0071] The solid electrolyte may be, for example, the solid electrolyte 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 thickness of the solid electrolyte layer 23 is, for example, 10 μm or more, or preferably 30 μm or more. The thickness of the solid electrolyte layer 23 is, for example, 300 μm or less, or preferably 100 μm or less.

[0073] (2) Current Collectors 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] 3A and 3B , the current collector 3 has a conductor 31, an insulating member 32, and an adhesive layer 33. In other words, the positive electrode current collector 3A and the negative electrode current collector 3B each have 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 its peripheral portion. In other words, the positive electrode current collector 3A and the negative electrode current collector 3B each have a plurality of notches 34A, 34B, 34C, 34D, 34E, 34F, 34G, and 34H. The number of notches is not limited.

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

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

[0078] The laminated portion 311 extends in a direction perpendicular to the stacking direction. 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 stacking direction. The laminated portion 311 has a sheet shape. The laminated portion 311 has one side S1 and another side S2 in the stacking direction. In other words, the conductor 31 has one side S1 and another side S2 in the stacking direction. The laminated portion 311 is stacked 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 stacked 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 stacked 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 in the stacking direction. The laminated portion 311 has a plurality of edges E1, E2, E3, and E4.

[0079] Edge E1 is disposed at one end of the laminated 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 the laminated 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 the laminated 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 the laminated 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 arranged on an edge of the laminated portion 311. In this embodiment, the tab 312 is arranged on an edge E3 on one side 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 may be a separate member 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 positioned 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, or preferably 5 μm or more, and for example, 100 μm or less, or 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 Member 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 edge of the laminated portion 311 of the conductor 31. When viewed from the lamination direction, the insulating member 32 has a substantially rectangular frame shape. 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] When 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 , when 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. When 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 cells 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 cells 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, an adhesive layer 33 is laminated on the other surface S2 of the conductor 31 at the peripheral edge 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 stacked 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 equal to or less 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 materials for the adhesive layer 33 include resins such as acrylic, polyimide, and silicone, and nonwoven fabrics impregnated with these resins.

[0092] (2-4) Notches 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 extends 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 toward the edge E2 of the conductor 31 in the first orthogonal direction. Each of the notches 34A and 34B extends in the first orthogonal direction to between the portions 32A and 32B of the insulating member 32. The insulating member 32 is interrupted at the portions 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 extends 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 in the first orthogonal direction to between the portion 32A and the portion 32B of the insulating member 32. The insulating member 32 is interrupted at the portions 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 extends 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 in the second orthogonal direction from the edge E3 toward the edge E4 of the conductor 31. 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 portions 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 extends from the edge E4 of the conductor 31 to the inside of the insulating member 32. 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 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 portions 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 cells 2 and the current collectors 3 are stacked, the cells 2 are arranged between the notches 34A, 34B and the notches 34C, 34D in the first orthogonal direction. When the cells 2 and the current collectors 3 are stacked, the cells 2 are arranged 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 Electrode Lead and Negative Electrode Lead As shown in Fig. 1A, a portion of the positive electrode lead 4 is exposed from the exterior packaging material 6. As shown in Fig. 4, the positive electrode lead 4 is joined to a positive electrode tab 312A within the exterior packaging material 6. This electrically connects the positive electrode lead 4 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 packaging material 6. The negative electrode lead 5 is joined to a negative electrode tab 312B (see Fig. 3A) inside the exterior packaging material 6. This allows the negative electrode lead 5 to be 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] The positive electrode lead 4 and the negative electrode lead 5 each have, for example, a substantially rectangular flat plate shape. Examples of materials for the positive electrode lead 4 and the negative electrode lead 5 include pure metals and alloys. Examples of pure metals include copper, nickel, aluminum, gold, and platinum. Examples of alloys include alloys of the above 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-plated layer and a gold-plated layer.

[0101] 1A and 1B, an exterior material 6 covers the laminate of the cells 2 and the 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. Method for Manufacturing All-Solid-State Battery 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 forming process (see FIGS. 5A to 6A ), a pressing process (see FIG. 6B ), a cutting process, a peeling process (see FIG. 6C ), a stacking 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 Step In the cell formation step, the cells 2 are formed on the first substrate F1 by dry printing. Specifically, the cells 2 are formed on the first substrate F1 by electrostatic screen printing.

[0105] Specifically, first, a positive electrode composite is prepared by mixing a powder of a positive electrode active material with a powder of a solid electrolyte. Then, a negative electrode composite is prepared by mixing a powder of a negative electrode active material with a powder of a solid electrolyte. The positive electrode composite and the negative electrode composite do not contain a resin such as a binder or a liquid such as an organic solvent. The positive electrode composite is preferably composed of a powder of a positive electrode active material and a powder of a solid electrolyte. The negative electrode composite 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 openings OP of the screen SC having a predetermined volume are filled with the positive electrode composite material M1.

[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] The order in which the positive electrode layer 21, the negative electrode layer 22, and the solid electrolyte layer 23 are formed is not limited as long as the cell 2 can be formed. 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 process is performed after the cell formation process. As shown in Fig. 6B, in the pressing process, a second substrate F2 is laminated on the cell 2, and the resulting laminate L1 is pressed. The resulting 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 process is performed after the pressing process. In the cutting process, 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 Step The peeling step is performed after the cutting step. Note that 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 from the cell 2. In this embodiment, both the first substrate F1 and the second substrate F2 are peeled from the cell 2. Note that in order to prevent the cell 2 from collapsing, only one of the first substrate F1 and the second substrate F2 may be peeled from the cell 2.

[0117] (5) Stacking Step The stacking step is performed after the peeling step. That is, the method for manufacturing an all-solid-state battery includes a cell forming step, a pressing step, and a peeling step before the stacking 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 current collector 3A. Specifically, the first cell 2A is stacked on the conductor 31 of the positive electrode current collector 3A, inside the insulating member 32 of the positive electrode current collector 3A (first step). As a result, with the first cell 2A stacked on the conductor 31 of the positive electrode current collector 3A, the insulating member 32 of the positive electrode current collector 3A is disposed around the first cell 2A. Furthermore, with the first cell 2A stacked on the positive electrode current collector 3A, the positive electrode layer 21 (see FIG. 6C ) of the first cell 2A contacts the conductor 31 of the positive electrode current 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 at one end of the first cell 2A in the first orthogonal direction. Specifically, the first cell 2A is pushed toward the jigs RA and RB from the other side in the first orthogonal direction using the jigs RC and RD. At this time, the jig RC enters the notch 34C, and the jig RD enters the notch 34D. By contacting the edge E11 with 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 at one end of the first cell 2A in the second orthogonal direction. Specifically, the first cell 2A is pushed toward the jigs RE and RF from the other side in the second orthogonal direction using the jigs RG and RH. At this time, the jig RG enters the notch 34G, and the jig RH enters the notch 34H. By bringing the edge E12 into contact with 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 stacked on the negative electrode layer 22 of the first cell 2A (second step), and 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 stacked 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). 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 way, 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 step is completed by stacking the desired number of cells 2 and current collectors 3 .

[0129] (5) Positive Electrode Tab Fixing Step and Negative Electrode Tab Fixing Step The positive electrode tab fixing step and the negative electrode tab fixing step are performed after the stacking step.

[0130] In the positive electrode tab fixing step, all the positive electrode tabs 312A are fixed to the stack L2 of the cells 2, the positive electrode laminated portion 311A, and the negative electrode laminated 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 on the furthest 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 on the furthest side (a position that extends straight toward the positive electrode lead 4) in the stacking direction.

[0132] In other embodiments, the unfolded positive electrode tab 312A may not be located at the furthest side (bottom) in the stacking direction depending on the position of the positive electrode lead 4. 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 of the positive electrode tabs 312A may be folded (i.e., without folding) except for the positive electrode tab 312A located in the center in 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 unfolded positive electrode tab 312A may be located in the center in 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 portion 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 the present 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 from 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 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 stack L2 so that all of the positive electrode second portions 3122A are overlapped. The method for fixing all of the positive electrode first portions 3121A to the stack L2 is not limited. For example, all of the positive electrode first portions 3121A may be fixed to the stack L2 using 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 stack 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 stack L2, and all of the positive electrode first portions 3121A may be fixed to the stack L2 by the inner surface of the recess 100A. Specifically, the inner surface of the recess 100A presses the bundle of positive electrode first portions 3121A toward the other side in the second orthogonal direction so as to bring them closer to the stack L2. When the exterior material 6 of the all-solid-state battery 1 is a drawn 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 of 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, and therefore will not be illustrated in the drawings.

[0139] In the negative electrode tab fixing step, similar 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, similar 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 in the stacking direction (a place that goes straight toward the negative electrode lead 5).

[0140] Like the unfolded positive electrode tab 312A, the unfolded negative electrode tab 312B does not have to be located at the furthest 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 position going straight toward the negative electrode lead 5).

[0141] The negative electrode first portion 3121B extends from the negative electrode laminate portion 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 the present embodiment, the negative electrode first portion 3121B is disposed on one side of the laminate L2 in a second orthogonal direction. The negative electrode first portion 3121B is disposed away from the positive electrode first portion 3121A in the first orthogonal 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 from 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 the 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 different direction from 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] Negative electrode bent portion 3123B connects negative electrode first portion 3121B and negative electrode second portion 3122B. Negative electrode bent portion 3123B bends from negative electrode first portion 3121B toward negative electrode second portion 3122B.

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

[0145] In the present embodiment, the fixing member 100 is placed over the stack L2, and all of the positive electrode first portions 3121A and all of the negative electrode first portions 3121B are fixed to the stack L2 by the inner surfaces of the recesses 100A. In this way, 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 Step and Negative Electrode Welding Step The positive electrode welding step is performed after the positive electrode tab fixing step. The negative electrode welding step is performed after the negative electrode tab fixing step.

[0148] 10C , in the positive electrode welding step, with all of the positive electrode first portions 3121A fixed to the laminate L2, all of the positive electrode second portions 3122A and the positive electrode tab 312A located on the furthest side in the stacking direction (the unbent positive electrode tab 312A extending straight toward the positive electrode lead 4) are ultrasonically welded to the positive electrode lead 4. In other words, with all of the positive electrode first portions 3121A fixed to the laminate L2, a bundle of all of 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 of 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. In other words, in the positive electrode welding process, 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 will be explained without illustration.

[0151] In the negative electrode welding step, with all of the negative electrode first portions 3121B fixed to the laminate L2, all of the negative electrode second portions 3122B and the negative electrode tab 312B located on the furthest side in the stacking direction (the unbent negative electrode tab 312B extending straight toward the negative electrode lead 5) are ultrasonically welded to the negative electrode lead 5 (see FIG. 1A ). In other words, with all of the negative electrode first portions 3121B fixed to the laminate L2, a bundle of all of 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 of 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. In other words, 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 also 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 packaging material 6.

[0155] This completes the production of the 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 ultrasonically welding the positive electrode tab 312A and the positive electrode lead 4 together, the 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. 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 the positive electrode welding step, the positive electrode second portion 3122A is ultrasonically welded to the positive electrode lead 4 in a state in which the positive electrode first portion 3121A is fixed to the laminate L2.

[0158] By fixing the positive electrode first portion 3121A to the laminate L2, the restoration of the positive electrode tab 312A in the positive electrode welding step is suppressed. Therefore, there is no need to hold the restoring positive electrode tab 312A 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 prevented.

[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 , the stack L2 is covered with a fixing member 100 having a recess 100A capable of accommodating the stack L2, and all of the positive electrode first portions 3121A and all of the negative electrode first portions 3121B are fixed to the stack 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 while it is placed in the exterior packaging material 6, and further, after the positive electrode welding process and the negative electrode welding process, the laminate L2 can be packed using the exterior packaging material 6 that was 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 come into contact with positive electrode bent portion 3123A but comes into contact with 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 come into contact with negative electrode bent portion 3123B but comes into contact with 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 prevented.

[0169] (5) According to the method for manufacturing 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 stacked 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, thereby forming the cell 2 on the first substrate F1 by a dry process (cell formation process).

[0171] 6B, a second substrate 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 stacked (stacking step).

[0174] This allows the manufacture of an all-solid-state battery 1 having cells 2 manufactured by a dry method.

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

[0176] As a result, the manufacturing method of 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, as shown in FIG. 7A , the stacking step includes a first step of stacking the first cell 2A on the positive electrode current collector 3A, and as shown in FIG. 8B , a second step of stacking the negative electrode current collector 3B on the first cell 2A, and a third step of stacking the second cell 2B on the negative electrode current collector 3B.

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

[0179] This makes it possible to manufacture 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.

[0180] (7) According to the manufacturing method of 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 the current collector 3 in which the insulating member 32 is laminated around the periphery of the 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 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 can prevent short circuits 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 out from the edge E1 of the conductor 31 to the inside of the insulating member 32, and notches 34E and 34F cut out 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 current 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, jig RE is placed in notch 34E, jig RF is placed in notch 34F, and cell 2 is positioned relative to positive electrode current collector 3A in the second direction so that edge E12 of cell 2 contacts 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 allows the cell 2, the positive electrode current collector 3A, and the negative electrode current collector 3B to be easily stacked while preventing the cell 2 from being misaligned relative to the positive electrode current collector 3A and the negative electrode current collector 3B.

[0190] 4. Modifications Modifications will be described below. In the modifications, the same components 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 of the positive electrode first portions 3121A may be fixed to the laminate L2 with adhesive tape. Also, in the negative electrode tab fixing step, all of the negative electrode first portions 3121B may be fixed to the laminate L2 with adhesive tape.

[0192] The above invention is provided as an exemplary embodiment of the present invention, but it is merely an example and should not be interpreted as being limiting. Modifications of the present invention that are obvious to those skilled in the art are included in the scope of the following claims.

[0193] The method for producing an all-solid-state battery of the present invention can be used to produce all-solid-state batteries.

[0194] REFERENCE SIGNS LIST 1 all-solid-state battery 2 cell 21 positive electrode layer 22 negative electrode layer 23 solid electrolyte layer 2A first cell 2B second cell 3A positive electrode current collector 31 conductor 32 insulating member 33 adhesive layer 311A ​​positive electrode laminated portion 312A positive electrode tab 3121A positive electrode first portion 3122A positive electrode second portion 3123A positive electrode bent portion 3B negative electrode current collector 311B negative electrode laminated portion 312B negative electrode tab 3121B negative electrode first portion 3122B negative electrode second portion 3123B negative electrode bent portion 4 positive electrode lead 5 negative electrode lead 6 exterior material 100 fixing member 100A recess F1 first substrate F2 second substrate H horn L1 laminate L2 Laminate RA~RH Jig S1 One side S2 Other side

Claims

1. A lamination process 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 in a first direction, a plurality of positive electrode current collectors each having a positive electrode laminate portion laminated 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 laminated 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 process 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 the laminate of the cell, the positive electrode laminate portion, and the negative electrode laminate 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, and fixing all of the positive electrode first portions to the laminate; a 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 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 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.

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

5. The method for manufacturing an all-solid-state battery according to claim 1, 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.

6. The method for producing an all-solid-state battery according to claim 1, 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 comprises, prior to 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.

7. The method for producing an all-solid-state battery according to claim 1, 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 subsequent to 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 subsequent to the second step.

8. The method for producing an all-solid-state battery according to claim 1, wherein the positive electrode current collector and the negative electrode current collector have a conductor and an insulating member laminated on peripheral portions of the conductor, and in the laminating step, the cell is laminated on the conductor.

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

10. The method for producing an all-solid-state battery according to claim 8, wherein the positive electrode collector and the negative electrode 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 and the cell is positioned relative to the positive electrode collector or the negative electrode collector so that an edge of the cell contacts the jig.

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