Manufacturing method for all-solid-state batteries

Abstract

To provide a manufacturing method of an all-solid battery capable of efficiently increasing the adhesion between the layers of a battery laminate while restraining the warpage of the battery laminate.SOLUTION: A disclosed manufacturing method of an all-solid battery includes the steps of: enclosing a battery laminate in a laminate film container to obtain an inclusion body; laminating support plates on both outer surfaces of the inclusion body to sandwich the inclusion body with the support plates; and compressing the inclusion body by applying an isotropic pressure to the inclusion body while abutting the inclusion body and the support plate.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing an all-solid-state battery. In particular, the present disclosure relates to a method for manufacturing a stacked type all-solid-state battery. [Background technology]

[0002] Lithium-ion batteries are used as small batteries with high energy density. Among lithium-ion batteries, all-solid-state batteries, in which the electrolyte is replaced with a solid electrolyte, are attracting particular attention. This is because all-solid-state batteries use a solid electrolyte instead of the conventional electrolyte, and are expected to further increase the energy density.

[0003] An all-solid-state battery is manufactured, for example, by stacking a negative electrode current collector, a negative electrode active material layer, a solid electrolyte layer, a positive electrode active material layer, and a positive electrode current collector in this order to obtain a battery stack. In an all-solid-state battery, lithium ions move between the layers of the battery stack. In order to increase the efficiency of lithium ion movement, it is necessary to increase the adhesion between the layers. For this reason, in the manufacture of an all-solid-state battery, it is common and widespread to compress the battery stack using a press device and / or a roll press device. In recent years, the use of isotropic pressure application has been considered in order to further increase the adhesion between the layers of the battery stack.

[0004] For example, Patent Document 1 discloses a method for manufacturing an all-solid-state battery, which includes applying an isostatic pressure to a battery laminate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-121558 A Summary of the Invention [Problem to be solved by the invention]

[0006] The manufacturing method of an all-solid-state battery disclosed in Patent Document 1 (hereinafter simply referred to as "the manufacturing method of Patent Document 1") discloses that a support plate is laminated on one side of a battery stack and isostatic pressure is applied to the battery stack. Patent Document 1 also discloses that when applying the isostatic pressure, the battery stack and the support plate are enclosed together in a laminate film container.

[0007] In the manufacturing method of Patent Document 1, it was necessary to open the laminate film container after the application of isotropic pressure and take out the battery stack and the support plate, which resulted in poor manufacturability. In addition, a large amount of waste from the laminate film container was generated, which caused an increase in manufacturing costs. If the battery stack and the support plate were not enclosed together in the laminate film container, the support plate could shift when the isotropic pressure was applied. In addition, if the support plate was not used, warping occurred in the battery stack after the isotropic pressure was applied. In addition, when preparing the battery stack, the end faces of each layer of the battery stack were prone to shifting, which could cause a short circuit between the end faces of the positive electrode body and the negative electrode body that constitute the battery stack.

[0008] In view of the above, the present inventors have found that there is a need for a method for manufacturing an all-solid-state battery that can suppress warping of the battery stack and efficiently increase adhesion between the layers of the battery stack.The present inventors have also found that there is a need for a method for manufacturing an all-solid-state battery that can suppress misalignment of the layers of the battery stack when preparing the battery stack and avoid short-circuiting between the end faces of the positive electrode body and the negative electrode body that constitute the battery stack.

[0009] The present disclosure has been made to solve the above problems. That is, the present disclosure aims to provide a method for manufacturing an all-solid-state battery that can suppress warping of the battery stack and efficiently increase adhesion between the layers of the battery stack. Another aim is to provide a method for manufacturing an all-solid-state battery that can suppress misalignment of the layers of the battery stack and avoid short circuits between the end faces of the positive electrode body and the negative electrode body when preparing the battery stack. [Means for solving the problem]

[0010] The present inventors have conducted intensive research to achieve the above object and have completed a method for producing an all-solid-state battery according to the present disclosure. The method for producing an all-solid-state battery according to the present disclosure includes the following aspects. <1> Encapsulating the battery stack in a laminate film container to obtain an encapsulated body; Laminating support plates on both outer surfaces of the enclosure and sandwiching the enclosure between the support plates; and applying isotropic pressure to the inclusion body while the inclusion body and the support plate are in contact with each other to compress the inclusion body; Including, How solid-state batteries are manufactured. <2> The method for producing an all-solid-state battery according to <1>, wherein the support plate is clamped with an elastic clip, and the encapsulant and the support plate are brought into contact with each other by a repulsive force of the elastic clip. <3> The method for producing an all-solid-state battery according to <1>, further comprising stacking an auxiliary support plate, via an elastic body, on at least one of the outer surfaces of the support plate that sandwiches the encapsulation body, thereby bringing the encapsulation body and the support plate into contact with each other by a repulsive force of the elastic body. <4> The method for producing an all-solid-state battery according to any one of <1> to <3>, wherein the isotropic pressure is applied in a pressure vessel, and the encapsulation body is disposed in the pressure vessel while a stacking surface of the battery stack is non-horizontal. <5> forming a positive electrode active material layer on one or both sides of a positive electrode current collector to prepare a positive electrode layer; forming a negative electrode active material layer on one or both sides of a negative electrode current collector to prepare a negative electrode layer; Providing a first solid electrolyte layer and a second solid electrolyte layer; and preparing the battery stack by contacting the positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer via the first solid electrolyte layer and disposing a second solid electrolyte layer on at least one of an end face of the positive electrode layer and an end face of the negative electrode layer; Includes When preparing the battery stack, an insulating layer is provided on the outer periphery of the second solid electrolyte layer, and end faces of the layers of the battery stack are aligned at at least two points on the outer periphery of the battery stack, thereby positioning the layers in the stacking direction. The method for producing the all-solid-state battery according to any one of items <1> to <4>. <6> Forming a positive electrode active material layer on one or both sides of a positive electrode current collector to prepare a positive electrode layer; forming a negative electrode active material layer on one or both sides of a negative electrode current collector to prepare a negative electrode layer; Providing a first solid electrolyte layer; and preparing the battery stack by contacting the positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer via the first solid electrolyte layer; Includes When preparing the battery stack, an insulating layer is provided on the outer periphery of the first solid electrolyte layer, and end faces of the layers of the battery stack are aligned at at least two points on the outer periphery of the battery stack, thereby positioning the layers in the stacking direction. The method for producing the all-solid-state battery according to any one of items <1> to <4>. <7> forming a positive electrode active material layer on one or both sides of a positive electrode current collector to prepare a positive electrode layer; forming a negative electrode active material layer on one or both sides of a negative electrode current collector to prepare a negative electrode layer; Providing a first solid electrolyte layer and a second solid electrolyte layer; and preparing a battery stack by contacting the positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer via the first solid electrolyte layer and disposing a second solid electrolyte layer on at least one of an end face of the positive electrode layer and an end face of the negative electrode layer; Includes When preparing the battery stack, an insulating layer is provided on the outer periphery of the second solid electrolyte layer, and end faces of the layers of the battery stack are aligned at at least two points on the outer periphery of the battery stack, thereby positioning the layers in the stacking direction. How solid-state batteries are manufactured. <8> forming a positive electrode active material layer on one or both sides of a positive electrode current collector to prepare a positive electrode layer; forming a negative electrode active material layer on one or both sides of a negative electrode current collector to prepare a negative electrode layer; Providing a first solid electrolyte layer; and preparing a battery stack by contacting the positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer through the first solid electrolyte layer; Includes When preparing the battery stack, an insulating layer is provided on the outer periphery of the first solid electrolyte layer, and end faces of the layers of the battery stack are aligned at at least two points on the outer periphery of the battery stack, thereby positioning the layers in the stacking direction. How solid-state batteries are manufactured. <9> The method for producing an all-solid-state battery according to <7> or <8>, further comprising applying an isostatic pressure to the battery stack. Effect of the Invention

[0011] According to the present disclosure, when isotropic pressure is applied to the inclusion body, the inclusion body and the support plate are kept in contact with each other in accordance with the compression of the inclusion body, so that warping of the battery stack after the application of the isotropic pressure can be suppressed. In addition, since the outer surface of the inclusion body is sandwiched by the support plate, it is not necessary to remove the support plate from inside the laminate film container after the application of the isotropic pressure. From these facts, according to the present disclosure, it is possible to provide a method for manufacturing an all-solid-state battery that can suppress warping of the battery stack and efficiently increase adhesion between each layer of the battery stack. And, it is possible to provide a method for manufacturing an all-solid-state battery that can suppress misalignment of each layer of the battery stack and avoid short-circuiting between the end face of the positive electrode body and the end face of the negative electrode body by preparing the battery stack by disposing an insulating layer at a predetermined position and positioning the stacking direction at a predetermined position. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an explanatory diagram that illustrates a schematic diagram of an example of an embodiment of the manufacturing method for an all-solid-state battery according to the present disclosure. [Diagram 2] FIG. 2 is an explanatory view that illustrates a schematic diagram of another embodiment of the method for producing an all-solid-state battery according to the present disclosure. [Diagram 3]FIG. 3 is an explanatory diagram showing a cross section of the enclosure sandwiched between a support plate and an auxiliary support plate in the state shown in FIG. [Figure 4] FIG. 4 is an explanatory view that illustrates a schematic diagram of one embodiment of applying isotropic pressure in a pressure vessel in the manufacturing method of an all-solid-state battery according to the present disclosure. [Diagram 5] FIG. 5 is an explanatory view that illustrates a schematic diagram of another embodiment in which isotropic pressure is applied in a pressure vessel in the production method of an all-solid-state battery according to the present disclosure. [Figure 6] FIG. 6 is a graph showing the height profile and curvature distribution for the all-solid-state battery sample of the example. [Figure 7] FIG. 7 is a graph showing the height profile and curvature distribution for the all-solid-state battery sample of the comparative example. [Figure 8] FIG. 8 is an explanatory diagram that illustrates an example of a conventional method for producing an all-solid-state battery. [Figure 9] FIG. 9 is an explanatory diagram that illustrates a schematic diagram of another example of a conventional method for producing an all-solid-state battery. [Figure 10A] FIG. 10A is an explanatory diagram that shows a cross section of one example of a method for obtaining a battery stack by forming positive electrode active material layers on both sides of a positive electrode current collector and forming negative electrode active material layers on both sides of a negative electrode current collector. [Figure 10B] FIG. 10B is an explanatory diagram that shows a schematic cross section of a battery stack obtained by the method shown in FIG. 10A. [Figure 11A] FIG. 11A is an explanatory diagram that shows a schematic cross section of one example of a method for obtaining a battery stack by forming a positive electrode active material layer on one side of a positive electrode current collector and forming negative electrode active material layers on both sides of a negative electrode current collector. [Figure 11B] FIG. 11B is an explanatory diagram that shows a schematic cross section of a battery stack obtained by the method shown in FIG. 11A. [Figure 12A] FIG. 12A is an explanatory diagram that illustrates a schematic top surface of an example of a positive electrode layer used in the method shown in FIG. 10A. [Figure 12B] FIG. 12B is an explanatory diagram that illustrates a schematic top surface of an example of the negative electrode layer used in the method shown in FIG. 10A. [Figure 12C] FIG. 12C is an explanatory diagram that illustrates a schematic top surface of an example of a first solid electrolyte layer used in the method shown in FIG. 10A. [Figure 12D] FIG. 12D is an explanatory diagram that illustrates a schematic top surface of an example of an insulating layer used in the method shown in FIG. 10A. [Figure 12E] 12E is an explanatory diagram showing a top view of a positioning method for preparing a battery stack using the positive electrode layer of FIG. 12A, the negative electrode layer of FIG. 12B, the solid electrolyte layer of FIG. 12C, and the insulating layer of FIG. 12D. [Figure 13] FIG. 13 is an explanatory diagram showing a top view of another embodiment of the positioning method. [Figure 14] FIG. 14 is an explanatory diagram showing a top view of yet another embodiment of the positioning method. [Figure 15] FIG. 15 is an explanatory diagram showing a cross section of the second solid electrolyte layer, illustrating a method for forming the second solid electrolyte layer that is different from that shown in FIG. 10A. [Figure 16] FIG. 16 is an explanatory diagram showing a cross section of an example of an embodiment in which the second solid electrolyte layer is omitted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the method for producing an all-solid-state battery according to the present disclosure will be described in detail. Note that the embodiment described below does not limit the method for producing an all-solid-state battery according to the present disclosure.

[0014] Without being bound by theory, the reason why the manufacturing method for the all-solid-state battery disclosed herein (hereinafter, may be referred to as the "manufacturing method of the present disclosure") can suppress warping of the battery stack and efficiently increase adhesion between the layers of the battery stack will be described with reference to the drawings.

[0015] The application of isotropic pressure is performed by applying a high pressure pressure medium to the target object. Therefore, when applying isotropic pressure to a battery stack as the target object, it is necessary to prevent the battery stack from being damaged or contaminated by the pressure medium. For this reason, the battery stack is enclosed in a laminate film container and isotropic pressure is applied to the enclosed object.

[0016] If a battery stack is enclosed in a laminate film container and isotropic pressure is applied to it, the battery stack will warp. Therefore, by attaching a support plate to the battery stack and applying isotropic pressure to it, warping of the battery stack can be suppressed.

[0017] FIG. 8 is an explanatory view that shows a schematic diagram of an example of a conventional method for manufacturing an all-solid-state battery, and FIG. 9 is an explanatory view that shows a schematic diagram of another example of a conventional method for manufacturing an all-solid-state battery.

[0018] When applying isostatic pressure to the battery stack with a support plate attached, it is necessary to prevent the battery stack from separating from the support plate. For this reason, in the conventional technology, for example, in the manufacturing method of Patent Document 1, the battery stack 10 and the support plate 40 are enclosed together in a laminate film container 20 as shown in FIG. 8. In the example shown in FIG. 8, the battery stack 10 is enclosed in the laminate film container 20, the support plate 40 is attached to the enclosure 30, and the enclosure 30 is further enclosed in the laminate film container 20 to prevent the enclosure 30 from separating from the support plate 40. From the viewpoint of preventing the battery stack 10 from separating from the support plate 40, the support plate 40 may be directly attached to the battery stack 10 as shown in FIG. In the conventional technology, in any case, it was necessary to enclose the battery stack 10 or the enclosure 30 and the support plate 40 together in the laminate film container 20 as shown in FIG. 8 and FIG. 9. Since the support plate 40 is not necessary as a component of the all-solid-state battery, it was necessary to remove the support plate 40 from the laminate film container 20 after the application of the isotropic pressure.

[0019] The present inventors have therefore found the following. This finding will be described with reference to the drawings. Figure 1 is an explanatory diagram that illustrates a schematic diagram of an example of an embodiment of the manufacturing method for an all-solid-state battery of the present disclosure.

[0020] In the manufacturing method of the all-solid-state battery of the present disclosure, for example, as shown in FIG. 1, the battery stack 10 is enclosed in a laminate film container 20, and the outer surfaces of both sides of the inclusion body 30 are sandwiched by a support plate 40. Then, an isotropic pressure is applied to the inclusion body 30 sandwiched by the support plate 40, so that the inclusion body 30 and the support plate 40 are maintained in contact even when the inclusion body 30 is compressed. To achieve this, a pressure is applied to the support plate 40 in addition to the application of the isotropic pressure, so that the inclusion body 30 and the support plate 40 are maintained in contact. Specifically, for example, in the embodiment shown in FIG. 1, the inclusion body 30 sandwiched by the support plate 40 is further sandwiched by an elastic clip 50. This realizes that the inclusion body 30 is compressed by applying an isotropic pressure to the inclusion body 30 while the inclusion body 30 and the support plate 40 are in contact with each other.

[0021] When the enclosure 30 sandwiched between the support plate 40 is further sandwiched between the elastic clip 50, a slight pressure can be applied to the enclosure 30 through the support plate 40 by the elastic clip 50. However, the battery stack 10 in the enclosure 30 is hardly compressed by the pressure applied by the elastic clip 50 alone, and as a result, the layers in the battery stack 10 cannot be sufficiently bonded to each other. Therefore, when an isostatic pressure is applied to the enclosure 30 and the support plate 40 while they are sandwiched between the elastic clip 50, the enclosure 30 is compressed, and the layers in the battery stack 10 can be sufficiently bonded to each other. At this time, since the support plate 40 is sandwiched between the elastic clip 50, the two sandwiching parts of the elastic clip 50 are separated from each other, and a repulsive force that tries to narrow the gap acts on the support plate 40. Due to this repulsive force, even if the enclosure 30 is compressed when the isostatic pressure is applied, the enclosure 30 and the support plate 40 can be maintained in contact with each other. That is, the inclusion body 30 can be compressed by applying an isotropic pressure to the inclusion body 30 while the inclusion body 30 and the support plate 40 are in contact with each other.

[0022] The present inventors have found that by applying isotropic pressure to the enclosure 30 while the enclosure 30 and the support plate 40 are in contact with each other, the support plate 40 does not separate from or shift from the enclosure 30 during the application of the isotropic pressure. This makes it possible to avoid separation and / or shifting of the enclosure 30 and the support plate 40, even if the battery stack 10 or the enclosure 30 is not enclosed in the laminate film container 20 together with the support plate 40, as in the manufacturing method of Patent Document 1. This makes it unnecessary to remove the support plate 40 from the laminate film container 20 after the application of the isotropic pressure, as in the manufacturing method of Patent Document 1. In other words, the present inventors have found that warping of the battery stack 10 can be efficiently avoided or suppressed, even if the battery stack 10 or the enclosure 30 is not enclosed in the laminate film container 20 together with the support plate 40, as in the manufacturing technique of Patent Document 1.

[0023] Next, the constituent elements of the method for producing an all-solid-state battery according to the present disclosure, which has been completed based on the findings and the like described above, will be described.

[0024] <<Manufacturing method of all-solid-state batteries>> The method for producing an all-solid-state battery according to the present disclosure includes an encapsulation body preparation step, an encapsulation body sandwiching step, and an isostatic pressure application step. Each of these steps will be described below.

[0025] <Inclusion body preparation step> First, an enclosure is prepared. Specifically, the battery stack is enclosed in a laminate film container to obtain an enclosure.

[0026] A well-known battery stack used in the manufacture of an all-solid-state battery can be selected. A preferred method for forming the battery stack will be described in detail later in "Battery Stack Preparation Step". Such a battery stack is obtained by stacking one or more unit batteries. Typically, the unit battery can be obtained by stacking an anode current collector, an anode active material layer, a solid electrolyte layer, a cathode active material layer, and a cathode current collector in this order. In this case, a well-known anode current collector, an anode active material layer, a solid electrolyte layer, a cathode active material layer, and a cathode current collector for an all-solid-state battery can be selected. Each of these will be described below, but is not limited to this.

[0027] ·Negative electrode current collector As the material of the negative electrode current collector, for example, Ag, Cu, Au, Al, Ni, Fe, stainless steel, Ti, etc., or an alloy thereof can be used. From the viewpoint of chemical stability, Cu and Ni are preferable, and when a sulfide-based solid electrolyte is used, Ni is particularly preferable from the viewpoint of avoiding sulfurization of the negative electrode current collector.

[0028] ·Negative electrode active material layer The negative electrode active material layer contains a negative electrode active material, and optionally a solid electrolyte and a binder. The negative electrode active material can be selected from well-known materials that function as a negative electrode active material for an all-solid-state battery, and is not particularly limited. The negative electrode active material can be selected from materials that can absorb and release metal ions, for example, lithium ions. The negative electrode active material can be, for example, metallic lithium, lithium alloys, carbon materials such as graphite or hard carbon, silicon metal, silicon alloys, or silicon materials such as Li4Ti5O 12(LTO), etc. These materials may be combined and selected. Examples of lithium alloys include LiSn, LiSi, LiAl, LiGe, LiSb, LiP, and LiIn. Metallic lithium means unalloyed lithium. Examples of silicon alloys include alloys with metal elements such as lithium, and may also be alloys with one or more metal elements selected from the group consisting of tin, germanium, and aluminum. Metallic silicon means unalloyed silicon. The negative electrode active material may be selected from other metal materials, such as indium, aluminum, or tin, or a combination thereof. When a graphite material, which is a crystalline carbon material, is selected as the negative electrode active material, the surface of the graphite may be amorphously coated.

[0029] Examples of the solid electrolyte include sulfide-based amorphous solid electrolytes, such as Li2S-P2S5, Li2O·Li2S·P2S5, Li2S, P2S5, Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-Li2S-P2O5, LiI-LiBr-Li2S-P2S5, and LiI-Li3PO4-P2S5; or oxide-based amorphous solid electrolytes, such as Li2O-B2O3-P2O 5、 Li2O-SiO2, etc.; or oxide-based crystalline solid electrolytes, such as LiI, Li3N, Li5La3Ta2O 12 , Li7Zr2O 12 , Li6BaLa2Ta2O 12 , LiPO (4-3 / 2w) N w (w<1), etc.; or sulfide-based crystalline solid electrolytes, such as Li7P3S 11 , Li 3.25 P 0.75 Glass ceramics such as S4, or Li 3.24 P 0.24 Ge 0.76S4 or other thio-LiSiO-based crystals, Li6PS5X (X=Cl, Br) or other crystals having an argyrodite-type crystal structure (hereinafter sometimes referred to as "argyrodite-type sulfide solid electrolytes"); or a combination thereof. From the viewpoint of high lithium ion conductivity and electrochemical stability, argyrodite-type sulfide solid electrolytes are preferred.

[0030] There is no particular restriction on the binder as long as it does not adversely affect the performance and manufacture of the all-solid-state battery. The binder may typically be one or more resins selected from the group consisting of fluorine-based resins and polyolefin-based resins, but is not limited thereto. From the viewpoint of dispersibility, fluorine-based resins, particularly polyvinylidene fluoride (PVDF), are preferred. Examples of fluorine-based resins include polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), perfluoroalkoxyalkane (PFA), and the like. These may be selected in combination. Examples of polyolefin-based resins include styrene butadiene rubber (SBR), polypropylene (PP), polyethylene (PE), and (meth)acrylic resins such as polymethyl methacrylate (PMMA), polymethyl acrylate, polybutyl acrylate (PBA), and polyacrylonitrile (PAN). These may be selected in combination.

[0031] The negative electrode active material layer may further contain, as desired, for example, a solvent for the binder, a conductive material, and the like.

[0032] The binder solvent is not particularly limited as long as it does not adversely affect the performance and production of the all-solid-state battery. Examples of the binder solvent include butyl butyrate, toluene, and methyl ethyl ketone (MEK), and may be a mixed solvent thereof.

[0033] The conductive material may be selected from carbon materials such as VGCF (Vapor Grown Carbon Fiber), acetylene black, Ketjen black, carbon nanotubes, or the like, or a combination thereof.

[0034] ·Solid electrolyte layer The solid electrolyte layer contains at least a solid electrolyte, and may optionally contain a binder, etc. Examples of the solid electrolyte used in the solid electrolyte layer include the solid electrolytes described in "Negative electrode active material layer."

[0035] Examples of binders include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), butylene rubber (BR), styrene-butadiene rubber (SBR), polyvinyl butyral (PVB), acrylic resin, etc. These may be used in combination. Also, heptane, etc., may be used as a solvent for these binders.

[0036] ·Cathode active material layer The positive electrode active material layer contains a positive electrode active material, and optionally a conductive material, a binder, and a solid electrolyte. The positive electrode active material can be selected from metal oxides containing lithium and at least one transition metal selected from manganese, cobalt, nickel, and titanium, such as lithium cobalt oxide, lithium nickel oxide, lithium manganate, or lithium nickel cobalt manganate, Li-Mn spinel substituted with a different element, lithium titanate, lithium metal phosphate, or a combination thereof.

[0037] The conductive material may be the conductive material described in "·Negative electrode active material layer". The solid electrolyte may be the solid electrolyte described in "·Negative electrode active material layer". In addition, the binder and its solvent may be the binder and its solvent described in "·Solid electrolyte layer".

[0038] ·Positive electrode current collector For the positive electrode current collector, reference can be made to the negative electrode current collector described in "Negative electrode current collector." Among them, aluminum is preferred as the positive electrode current collector from the viewpoint of chemical stability.

[0039] - Method for forming battery stack The method for forming the battery stack can be a method known in the art for manufacturing all-solid-state batteries. Below, a typical method for forming the battery stack will be briefly described, but the method is not limited to this.

[0040] A unit battery is formed by stacking the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer, and the positive electrode current collector in this order. There is no particular limitation on the stacking method. For example, a solid electrolyte layer is formed on the surface of a base plate, and the solid electrolyte layer side is bonded to one of the negative electrode active material layer and the positive electrode active material layer. Thereafter, the base plate of the solid electrolyte layer is peeled off, and the other of the negative electrode active material layer and the positive electrode active material layer is bonded to the surface of the solid electrolyte layer. A negative electrode current collector and a positive electrode current collector are attached to one surface of each of the negative electrode active material layer and the positive electrode active material layer in advance, and the surface of the solid electrolyte layer to which the negative electrode current collector and the positive electrode current collector are not attached is bonded.

[0041] The unit batteries may be used as the battery stack, or the unit batteries may be stacked and used as the battery stack. After forming the unit batteries and / or stacking the unit batteries, the unit batteries and / or the stack of unit batteries may be pre-pressed using a roll press or the like as desired. As described above, application of isotropic pressure is necessary to improve adhesion between the layers of the battery stack. By pre-pressing, damage to the battery stack can be suppressed when the battery stack is enclosed in a laminate film container or the like.

[0042] The negative electrode active material layer, the solid electrolyte layer, and the positive electrode active material layer can be formed by a method well known in the manufacture of all-solid-state batteries. Hereinafter, typical methods for forming these layers will be briefly described, but the methods are not limited to these.

[0043] The method for forming the negative electrode active material layer is to prepare a negative electrode mixture paste containing a negative electrode active material and optionally a solid electrolyte and a binder, apply the negative electrode mixture paste to the surface of the negative electrode current collector, and dry it. The negative electrode mixture paste may further optionally contain a binder solvent and a conductive material. The method for applying the negative electrode mixture is not particularly limited, and examples thereof include a doctor blade method, a metal mask printing method, an electrostatic application method, a dip coating method, a spray coating method, a roll coating method, a gravure coating method, and a screen printing method. These may be used in combination.

[0044] The method for forming the solid electrolyte layer includes a method of compressing and molding a powder or pellet of a raw material for forming the solid electrolyte layer containing at least a solid electrolyte. Alternatively, a method of applying a raw material paste for forming the solid electrolyte layer containing at least a solid electrolyte and a solvent to the surface of a base plate and drying the applied paste. The raw material for forming the solid electrolyte layer and the raw material paste for forming the solid electrolyte layer may optionally contain a binder or the like.

[0045] The method for forming the positive electrode active material layer includes preparing a positive electrode mixture paste containing at least a positive electrode active material, applying the positive electrode mixture paste to the surface of a positive electrode current collector, and drying the paste. The positive electrode mixture paste may optionally contain a conductive material, a binder, and a solid electrolyte. The method for applying the positive electrode mixture paste to the surface of a positive electrode current collector can refer to the method for applying the negative electrode mixture paste to the surface of a negative electrode current collector.

[0046] The battery stack obtained as described above is enclosed in a laminate film container to obtain an enclosed body. To explain this in the embodiment shown in Fig. 1, for example, the battery stack 10 is enclosed in a laminate film container 20 to obtain an enclosed body 30.

[0047] The laminated film container is not particularly limited as long as it can apply isotropic pressure to the battery stack enclosed in the laminated film container. Typically, a well-known laminated film container used in an all-solid-state battery can be used, but is not limited thereto. Typically, an aluminum laminated film container or the like can be used.

[0048] <Inclusion body clamping process> Support plates are laminated on both outer surfaces of the enclosure, and the enclosure is sandwiched between the support plates. This will be described, for example, in the embodiment shown in FIG. 1. Support plates 40 are laminated on both outer surfaces of the enclosure 30, and the enclosure 30 is sandwiched between the support plates 40. The battery stack 10 is formed by laminating an anode current collector, an anode active material layer, a solid electrolyte layer, a cathode active material layer, and a cathode current collector in this order. Here, in the embodiment shown in FIG. 1, the anode current collector, the anode active material layer, the solid electrolyte layer, the cathode active material layer, and the cathode current collector are each laminated approximately horizontally. "Support plates are laminated on both outer surfaces of the enclosure" means that the support plates are laminated in the same manner as the anode current collector, the anode active material layer, the solid electrolyte layer, the cathode active material layer, and the cathode current collector. That is, "support plates are laminated on both outer surfaces of the enclosure and the enclosure is sandwiched between the support plates" means, for example, in the embodiment shown in Fig. 1, that the laminated surfaces of the support plates 40 are substantially horizontal. Therefore, in the embodiment shown in Fig. 1, this means that the long sides (horizontal sides) of the enclosure 30 are sandwiched between the support plates 40, but does not mean, for example, that the short sides (vertical sides) of the enclosure 30 are sandwiched between the support plates 40.

[0049] There is no particular limitation on the support plate 40 as long as it does not bend or deform in the isotropic pressure application step described later. The support plate 40 is preferably excellent in corrosion resistance against the pressure medium for applying the isotropic pressure. From this viewpoint, the support plate 40 is preferably made of, for example, aluminum, an aluminum alloy, stainless steel, or a combination thereof. Also, typically, the isotropic pressure is applied in a pressure vessel. If the support plate 40 is made of a material with high rigidity (high Young's modulus) and high strength, even a thin support plate 40 can avoid or suppress bending and deformation when the isotropic pressure is applied. If a thin support plate 40 is used, a large number of the enclosed bodies 30 sandwiched by the support plate 40 can be loaded into the pressure vessel. From this viewpoint, the support plate 40 is preferably made of, for example, stainless steel.

[0050] The thickness of the support plate 40 may be appropriately determined in accordance with the relationship between the type of material and the rigidity and strength of the support plate 40. The thickness of the support plate 40 may be, for example, 1 mm or more, 2 mm or more, 3 mm or more, 4 mm or more, or 5 mm or more, and may be 20 mm or less, 15 mm or less, 10 mm or less, 8 mm or less, or 6 mm or less.

[0051] <Isotropic coining process> While the inclusion body and the support plate are in contact with each other, an isotropic pressure is applied to the inclusion body to compress it. As described above, for example, in the embodiment shown in FIG. 1, the inclusion body and the support plate are maintained in contact with each other by the elastic clip 50 when the isotropic pressure is applied, but this is not limited to this. When the inclusion body and the support plate are maintained in contact with each other, a repulsive force of the elastic clip 50 is applied to the support plate 40 in addition to the application of the isotropic pressure. Such a repulsive force may be, for example, 0.001 MPa or more, 0.005 MPa or more, 0.01 MPa or more, 0.05 MPa or more, 0.1 MPa or more, or 0.5 MPa or more, and may be 5 MPa or less, 4 MPa or less, 3 MPa or less, 2 MPa or less, or 1 MPa or less. That is, a pressure is applied to the support plate 40 in addition to the application of the isotropic pressure by the repulsive force of the elastic clip 50 to maintain the inclusion body 30 and the support plate 40 in contact with each other.

[0052] Here, an embodiment different from that shown in FIG. 1 will be described. Fig. 2 is an explanatory diagram that shows a schematic diagram of another embodiment of the manufacturing method for an all-solid-state battery according to the present disclosure. Fig. 3 is an explanatory diagram that shows a schematic cross section of the encapsulation body 30 sandwiched between support plates 40a, 40b, 40c, and 40d and auxiliary support plate 45 from the state shown in Fig. 2.

[0053] As shown in FIG. 3, an auxiliary support plate 45 is further laminated on the outer surfaces of the support plates 40a, 40b, 40c, and 40d that sandwich the inclusion body 30 via an elastic body 55. As a result, the support plates 40a, 40b, 40c, and 40d maintain contact with the inclusion body 30 by the repulsive force (urging force) of the elastic body 55 during the application of the isotropic pressure. The repulsive force (urging force) of the elastic body may be of a degree that can maintain the contact between the inclusion body and the support plate, and may be, for example, 0.001 MPa or more, 0.005 MPa or more, 0.01 MPa or more, 0.05 MPa or more, 0.1 MPa or more, or 0.5 MPa or more, and may be 5 MPa or less, 4 MPa or less, 3 MPa or less, 2 MPa or less, or 1 MPa or less. That is, the repulsive force (urging force) of the elastic body 55 loads pressure on the support plate 40 in addition to the application of the isotropic pressure, thereby maintaining the contact between the inclusion body 30 and the support plate. The inclusion body 30 shown in Fig. 3 may be considered to be similar to the inclusion body 30 already described. In addition, in the embodiment shown in Fig. 3, the number of inclusion bodies 30 is three, but this is not limiting.

[0054] The battery stack 10 in the enclosure 30 is formed by stacking the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer, and the positive electrode current collector in this order. Here, for example, in the embodiment shown in FIG. 3, the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer, and the positive electrode current collector are arranged (stacked) approximately horizontally. "An auxiliary support plate is stacked on at least one of the outer surfaces of the support plate sandwiching the enclosure via an elastic body" means that the auxiliary support plate is stacked in the same manner as the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer, and the positive electrode current collector. Therefore, "An auxiliary support plate is stacked on at least one of the outer surfaces of the support plate sandwiching the enclosure via an elastic body" means that, for example, in the embodiment shown in FIG. 3, the stacking surface of the auxiliary support plate 45 is approximately horizontal. In addition, "at least one" means that, in the embodiment shown in Fig. 3, the auxiliary support plate is laminated on the upper outer surface (upper surface of support plate 40d) via elastic body 55, but is not limited to this. In other words, it means that the auxiliary support plate 45 may be laminated on both the upper and lower outer surfaces (both the upper surface of support plate 40d and the lower surface of support plate 40a) via elastic body 55.

[0055] Since the auxiliary support plate 45 is further laminated via the elastic body 55 on the outer surfaces of the support plates 40a, 40b, 40c, and 40d that sandwich the enclosure 30, a repulsive force (urging force) of the elastic body 55 is generated. However, the repulsive force of the elastic body 55 alone is not enough to compress the battery stack 10 in the enclosure 30, and the layers in the battery stack 10 cannot be sufficiently adhered to each other. Therefore, if an isotropic pressure is applied while the repulsive force of the elastic body is applied, the enclosure 30 is compressed, and the layers in the battery stack 10 can be sufficiently adhered to each other. At this time, since the repulsive force of the elastic body 55 is acting on the support plates 40a, 40b, 40c, and 40d separately from the application of the isotropic pressure, the abutment between the enclosure 30 and the support plate 40 can be maintained. In other words, the isotropic pressure can be applied to the enclosure 30 while the enclosure 30 and the support plate 40 are in abutment with each other.

[0056] There is no particular limitation on the method of generating a repulsive force in the elastic body 55 and applying this repulsive force to the support plate 40. For example, in the embodiment shown in FIG. 3, the support plate 40a farthest from the auxiliary support plate 45 and the auxiliary support plate 45 are fixed plates, and the support plates 40b, 40c, and 40d other than the support plate 40a farthest from the auxiliary support plate 45 are movable plates, so that the elastic body 55 generates a repulsive force. That is, the support plates 40b, 40c, and 40d other than the support plate 40a farthest from the auxiliary support plate 45 move due to the repulsive force of the elastic body 55. As a result, the contact between the inclusion body 30 and the support plates 40a, 40b, 40c, and 40d can be maintained by the repulsive force of the elastic body 55 during the application of the isotropic pressure.

[0057] In the embodiment shown in Fig. 3, a bolt 70 is fixed to the support plate 40a farthest from the auxiliary support plate 45, and through holes 42 are formed in the auxiliary support plate 45 and the support plates 40b, 40c, and 40d other than the support plate 40a farthest from the auxiliary support plate 45, and the bolt 70 is inserted through the through hole 42. Then, a nut 72 is fastened on the surface of the auxiliary support plate 45 opposite the support plates 40a, 40b, 40c, and 40d so that the elastic body 55 generates a repulsive force. In this manner, the auxiliary support plate 45 and the support plate 40a farthest from the auxiliary support plate 45 can be fixed plates, and the support plates 40b, 40c, and 40d other than the support plate 40a farthest from the auxiliary support plate 45 can be movable plates.

[0058] The magnitude of the isotropic pressure to be applied may be appropriately determined taking into consideration the area of ​​the stacking surfaces of the battery stack 10, etc., so that the layers of the battery stack 10 inside the enclosure 30 are sufficiently in close contact with each other. The isotropic pressure may be, for example, 10 MPa or more, 50 MPa or more, 100 MPa or more, 200 MPa or more, 300 MPa or more, or 400 MPa or more, and may be 1000 MPa or less, 900 MPa or less, 800 MPa or less, 700 MPa or less, 600 MPa or less, or 500 MPa or less.

[0059] The temperature at which the isostatic pressure is applied may be appropriately determined so that the layers of the battery stack 10 inside the enclosure 30 are sufficiently tightly adhered to each other and so that the battery stack 10 is not deteriorated. The temperature at which the isostatic pressure is applied may be, for example, 100°C or more, 120°C or more, 140°C or more, 160°C or more, 180°C or more, or 190°C or more, and may be 300°C or less, 280°C or less, 260°C or less, 240°C or less, 220°C or less, or 200°C or less.

[0060] The time for which the isostatic pressure is applied may be appropriately determined so as to ensure sufficient adhesion between the layers of the battery stack 10 inside the enclosure 30. The time for which the isostatic pressure is applied may typically be 0.5 minutes or more, 1 minute or more, 3 minutes or more, or 5 minutes or more, and may be 60 minutes or less, 30 minutes or less, or 10 minutes or less.

[0061] A known pressure medium can be used for applying the isotropic pressure. Examples of the pressure medium include gas, liquid, powder, and combinations thereof. The pressure medium is typically a liquid, and more typically, water, oil, and combinations thereof.

[0062] There is no particular limitation on the method of applying the isotropic pressure, and a known application method can be applied. Typically, the object is placed in a pressure vessel, and isotropic pressure is applied to the object in the pressure vessel. At this time, the enclosed body sandwiched between the support plates may be arranged in the pressure vessel so that the stacking surface of the battery stack is non-horizontal. This will be explained using the drawings. FIG. 4 is an explanatory diagram that shows a schematic diagram of one aspect of applying isotropic pressure in a pressure vessel in the manufacturing method of the all-solid-state battery of the present disclosure. FIG. 5 is an explanatory diagram that shows a schematic diagram of another aspect of applying isotropic pressure in a pressure vessel in the manufacturing method of the all-solid-state battery of the present disclosure.

[0063] FIG. 4 shows the state in which the enclosed body 30 and the like of the embodiment shown in FIG. 2 and FIG. 3 are loaded into the pressure vessel 60. Due to space limitations, the enclosed body 30 and the elastic body 55 are omitted. As shown in FIG. 4, typically, the lamination surface of each layer of the battery stack 10 in the enclosed body 30 is substantially horizontal, but this is not limited thereto, and the lamination surface may be non-horizontal. For example, as shown in FIG. 5, the lamination surface of each layer of the battery stack 10 in the enclosed body 30 may be substantially vertical. Note that, like FIG. 4, due to space limitations, FIG. 5 also omits the enclosed body 30 and the elastic body 55. In addition, the embodiment shown in FIG. 5 is similar to the embodiment in FIG. 4 except that the support plate 40 and the auxiliary support plate 45 are rectangular.

[0064] In the manufacturing method of the all-solid-state battery disclosed herein, the inclusion body 30 and the support plate 40 are kept in contact with each other even during the application of isotropic pressure. Therefore, even if the stacking surface is not horizontal as in the embodiment shown in Fig. 5, it is possible to avoid or suppress displacement of the inclusion body 30. Furthermore, even if the cross-sectional area of ​​the loading port (above the pressure vessel 60) of the pressure vessel 60 is smaller than the area of ​​the stacking surface of the battery stack 10 in the inclusion body 30 as in the embodiment shown in Fig. 5, the inclusion body 30 and the like can be loaded into the pressure vessel 60 by making the stacking surface vertical.

[0065] <Battery Stack Preparation Process> The battery stack may be formed as follows. This will be described with reference to the drawings. FIG. 10A is an explanatory diagram showing a cross section of an example of a method for obtaining a battery stack by forming a positive electrode active material layer on both sides of a positive electrode current collector and a negative electrode active material layer on both sides of a negative electrode current collector. FIG. 10B is an explanatory diagram showing a cross section of a battery stack obtained by the method shown in FIG. 10A. FIG. 11A is an explanatory diagram showing a cross section of an example of a case in which a positive electrode active material layer is formed on one side of a positive electrode current collector and a negative electrode active material layer is formed on both sides of a negative electrode current collector to obtain a battery stack. FIG. 11B is an explanatory diagram showing a cross section of a battery stack obtained by the method shown in FIG. 11A.

[0066] As shown in FIG. 10A, a positive electrode active material layer 110 is formed on both sides of a positive electrode collector 100 to prepare a positive electrode layer 120, and a negative electrode active material layer 210 is formed on both sides of a negative electrode collector 200 to prepare a negative electrode layer 220. Alternatively, as shown in FIG. 11A, a positive electrode active material layer 110 is formed on one side of a positive electrode collector 100 to prepare a positive electrode layer 120, and a negative electrode active material layer 210 is formed on both sides of a negative electrode collector 200 to prepare a negative electrode layer 220. Then, a first solid electrolyte layer 310 and a second solid electrolyte layer 320 are prepared. As shown in FIG. 11A, when a positive electrode active material layer 110 is formed on one side of a positive electrode collector 100 to prepare a positive electrode layer 120, the positive electrode collectors 100 are brought into contact with each other to obtain a positive electrode layer 120. When preparing the negative electrode layer 220 by forming the negative electrode active material layer 210 on one side of the negative electrode current collector 200, the negative electrode current collectors 200 are brought into contact with each other to obtain the negative electrode layer 220. The materials and formation methods of the positive electrode current collector 100, the positive electrode active material layer 110, the negative electrode current collector 200, the negative electrode active material layer 210, the first solid electrolyte layer 310, and the second solid electrolyte layer 320 are as already described.

[0067] 10A and 11A, the positive electrode active material layer 110 of the positive electrode layer 120 and the negative electrode active material layer 210 of the negative electrode layer 220 are brought into contact with each other via the first solid electrolyte layer 310, and a second solid electrolyte layer is disposed on the end surface of the positive electrode layer 120 to prepare the battery stack 10. In the embodiments of Fig. 10A and 11A, the second solid electrolyte layer 320 is formed by folding the outer peripheral edge portion of the first solid electrolyte layer 310, but this is not limiting. Details will be described later.

[0068] When preparing the battery stack 10, as shown in Fig. 10A and Fig. 11A, the insulating layer 400 is placed on the outer periphery 330 of the second solid electrolyte layer 320, and the insulating layer 400 is positioned in the stacking direction (the vertical direction in Fig. 10A and / or Fig. 11A) at least at two points on the outer periphery of the battery stack 10. There are no particular limitations on the material constituting the insulating layer 400 as long as the insulating layer 400 can insulate electrical conduction. Examples of materials constituting the insulating layer 400 include glass, mica, and insulating resins, and insulating resins, in particular insulating thermoplastic resins, are preferred from the viewpoint of durability when a pressing pressure and / or an isotropic pressure is applied.

[0069] The positioning in the stacking direction is performed by aligning the end faces of the layers of the battery stack 10 at at least two points on the periphery of the battery stack 10. This will be described with reference to the drawings. FIG. 12A is an explanatory diagram showing a schematic top view of an example of a positive electrode layer used in the method shown in FIG. 10A. FIG. 12B is an explanatory diagram showing a schematic top view of an example of a negative electrode layer used in the method shown in FIG. 10A. FIG. 12C is an explanatory diagram showing a schematic top view of an example of a solid electrolyte layer used in the method shown in FIG. 10A. FIG. 12D is an explanatory diagram showing a schematic top view of an example of an insulating layer used in the method shown in FIG. 10A. FIG. 12E is an explanatory diagram showing a top view of a positioning method when preparing a battery stack using the positive electrode layer of FIG. 12A, the negative electrode layer of FIG. 12B, the solid electrolyte layer of FIG. 12C, and the insulating layer of FIG. 12D.

[0070] As shown in Fig. 10A, a positive electrode active material layer 110 is formed on both sides of a positive electrode current collector 100 to prepare a positive electrode layer 120. At this time, as shown in Fig. 12A, a part of the positive electrode current collector 100 is made to protrude as a positive electrode current collector tab 102. Similarly, as shown in Fig. 12B, a part of the negative electrode current collector 200 is made to protrude as a negative electrode current collector tab 202. For ease of explanation, Fig. 10A shows a cross section at a portion where the positive electrode current collector tab 102 and the negative electrode current collector tab 202 are not present.

[0071] When preparing the battery stack 10 shown in FIG. 10A, a positioning jig 500 shown in FIG. 12E is used to align the end faces of each layer of the battery stack 10, thereby positioning each layer of the battery stack 10 in the stacking direction. The end faces of each layer of the battery stack 10 refer to the end faces of each layer that are exposed to the outer shape of the battery stack 10. In the embodiment shown in FIG. 10A, the end faces of each layer that are exposed to the outer shape of the battery stack 10 are the end faces of the negative electrode layer 220, part of the second solid electrolyte layer 320, and the insulating layer 400. In the following description, the end faces of each layer that are exposed to the outer shape of the battery stack 10 may be simply referred to as the "end faces of each layer."

[0072] 12E, positioning is performed over the entire outer periphery of the battery stack (positioning is performed at multiple locations on the outer periphery of the battery stack, excluding the positive and negative current collector tabs 102 and 202). Therefore, in order to perform this positioning in the embodiment shown in Fig. 12E, the outer shapes of the end faces of each layer exposed to the outer shape of the battery stack 10 are made approximately the same, excluding the areas where the positive and negative current collector tabs 102 and 202 are provided.

[0073] In the manufacturing method of the all-solid-state battery of the present disclosure, the positioning method is not limited to the embodiment shown in FIG. 12E (an embodiment in which the positioning is performed over the entire outer periphery of the battery stack, excluding the positive electrode current collector tab 102 and the negative electrode current collector tab 202). FIGS. 13 and 14 are explanatory views showing the top surface of another embodiment of the positioning method. In the embodiment shown in FIG. 13, two abutments 520a, 520b are used, and the end faces of each layer are abutted against these abutments 520a, 520b to align the portions of the end faces of each layer that contact the abutments 520a, 520b, thereby positioning the stacking direction of each layer. The arrangement positions of the two abutments 520a, 520b are not limited to the positions shown in FIG. 13, and may be, for example, the positions shown in FIG. 14. In addition, the number of abutments is not limited to two. That is, in the manufacturing method of the all-solid-state battery of the present disclosure, the end faces of each layer are aligned at least at two positions on the outer periphery of the battery stack 10, thereby positioning the stacking direction of each layer. The positioning points may be appropriately determined depending on the outer shape of each layer.

[0074] When positioning is performed at two locations, the angle between one positioning surface (e.g., the positioning surface of the butt 520a) and the other positioning surface (e.g., the positioning surface of the butt 520b) is defined as θ. In this case, θ is not 0° or 180° (see FIG. 13), but may be more than 0°, 10° or more, 20° or more, 30° or more, 40° or more, 50° or more, 60° or more, 70° or more, or 80° or more, and is preferably less than 180°, 170° or less, 160° or less, 150° or less, 140° or less, 130° or less, 120° or less, or 100° or less. In the embodiment shown in FIG. 14, θ is 90°. By setting θ to the above-mentioned preferred angle, it is possible to advantageously suppress the misalignment of each layer of the battery stack 10 in both the vertical and horizontal directions in FIG. 12E.

[0075] In this manner, in the embodiment shown in Fig. 10A, the battery stack 10 shown in Fig. 10B is obtained. In the embodiment shown in Fig. 11A, the battery stack 10 shown in Fig. 11B is obtained.

[0076] 10A and 11A, the second solid electrolyte layer 320 is disposed only on the end face of the positive electrode layer 120, but the second solid electrolyte layer 320 may be disposed only on the end face of the negative electrode layer 220. Also, the second solid electrolyte layer 320 may be disposed on both the end face of the positive electrode layer 120 and the end face of the negative electrode layer 220.

[0077] 10A and 11A, the first solid electrolyte layer 310 is in contact with both sides of the positive electrode layer 120, and the outer peripheral edge portions of both first solid electrolyte layers 310 are folded to form the second solid electrolyte layer 320, but the present invention is not limited to this. Another method for forming the second solid electrolyte layer 320 will be described with reference to the drawings. FIG. 15 is an explanatory diagram showing a cross section of the second solid electrolyte layer 320, which is formed by a method different from that of FIG. 10A.

[0078] In FIG. 15 , of the two first solid electrolyte layers 310 sandwiching the positive electrode layer 120, the lower first solid electrolyte layer 310 is left as is, and the upper first solid electrolyte layer 310 is folded to form the second solid electrolyte layer 320, and an insulating layer 400 is disposed around the outer periphery of the second solid electrolyte layer 320.

[0079] In the embodiment shown in FIG. 11A, the positive electrode active material layer 110 is formed on one side of the positive electrode collector 100 to obtain the positive electrode layer 120, and the negative electrode active material layer 210 is formed on both sides of the negative electrode collector 200 to obtain the negative electrode layer 220, but this is not limited thereto. For example, the positive electrode active material layer 110 may be formed on both sides of the positive electrode collector 100 to obtain the positive electrode layer 120, and the negative electrode active material layer 210 may be formed on one side of the negative electrode collector 200 to obtain the negative electrode layer 220. Alternatively, the positive electrode active material layer 110 may be formed on one side of the positive electrode collector 100 to obtain the positive electrode layer 120, and the negative electrode active material layer 210 may be formed on one side of the negative electrode collector 200 to obtain the negative electrode layer 220.

[0080] By using the second solid electrolyte layer 320 and disposing the insulating layer 400 on the outer periphery of the second solid electrolyte layer 320 to prepare the battery stack 10 as described above, the following can be achieved. That is, the battery stack 10 can be prepared quickly while suppressing deviation in the stacking direction of each layer, and short circuits at the ends of the positive electrode layer 120 and the negative electrode layer 220 can be avoided. This is particularly advantageous when the outer shape of the positive electrode layer 120 is smaller than the outer shape of the negative electrode layer 220, or when the outer shape of the negative electrode layer 220 is smaller than the outer shape of the positive electrode layer 120.

[0081] Furthermore, the second solid electrolyte layer 320 can be omitted by doing the following. This will be described with reference to the drawings. Fig. 16 is an explanatory diagram showing a cross section of one example of an embodiment in which the second solid electrolyte layer is omitted.

[0082] As shown in FIG. 16, the positive electrode active material layer 110 of the positive electrode layer 120 and the negative electrode active material layer 210 of the negative electrode layer 220 are brought into contact with each other through the first solid electrolyte layer 310 to prepare the battery stack 10. At this time, an insulating layer is provided on the outer periphery of the first solid electrolyte layer 310, and the end faces of each layer of the battery stack 10 are aligned at least at two points on the outer periphery of the battery stack 10 to position the stacking direction. The end faces of each layer of the battery stack 10 in this embodiment are the end faces of the positive electrode layer 120, the negative electrode layer 220, and the insulating layer 400. This embodiment makes it possible to prepare the battery stack 10 at high speed while suppressing deviation in the stacking direction of each layer, and to avoid short-circuiting at the end of the positive electrode layer 120 and the end of the negative electrode layer 220. This embodiment is effective when the outer shape of the positive electrode layer 120 and the outer shape of the negative electrode layer 220 are substantially the same.

[0083] Even if an isostatic pressure is applied directly to a battery assembly prepared in the manner described above in the <Battery Stack Preparation Step>, the adhesion between the layers of the battery stack can be efficiently increased.

[0084] Transformation In addition to what has been described so far, the manufacturing method of the all-solid-state battery of the present disclosure can be modified in various ways within the scope of the claims. For example, the embodiment shown in FIG. 1 and the embodiment shown in FIG. 3 may be simultaneously implemented. Specifically, the clamping body of the embodiment shown in FIG. 1 and the clamping body of the embodiment shown in FIG. 3 may be loaded into the same pressure vessel, and isotropic pressure may be applied to them. Note that the "clamping body" means, for example, the entire enclosure 30 clamped by the support plate 40 and the elastic clip 50 as in the embodiment shown in FIG. 1. Alternatively, it means the entire enclosure 30 clamped by the support plate 40 and the auxiliary support plate 45 as in the embodiment shown in FIG. 3. EXAMPLES

[0085] The method for producing an all-solid-state battery according to the present disclosure will be described in more detail below with reference to examples and comparative examples. Note that the method for producing an all-solid-state battery according to the present disclosure is not limited to the conditions used in the following examples.

[0086] <<Preparation of all-solid-state battery samples>> An all-solid-state battery sample was prepared as follows.

[0087] Example 1 1, an isostatic pressure was applied to the enclosure 30. The isostatic pressure was 980 MPa, and the temperature at which the isostatic pressure was applied was 190° C. As the battery stack 10 in the enclosure 30, 10 unit batteries were stacked.

[0088] Comparative Example The isostatic pressure was applied to the enclosure 30 as it was. That is, the isostatic pressure was applied to the enclosure 30 without attaching the support plate 40. The conditions for applying the isostatic pressure and the number of stacked unit cells were the same as in the example.

[0089] Example 2 An all-solid-state battery sample was prepared in the same manner as in Example 1, except that a battery laminate was prepared in the manner shown in FIG. 10A.

[0090] Example 3 An all-solid-state battery sample was prepared in the same manner as in Example 1, except that a battery laminate was prepared in the manner shown in FIG.

[0091] "evaluation" After the isotropic pressure was applied, the battery stack 10 was removed from the laminate film container 20 of the enclosure 30, and the height profile of the current collector surface (the stack surface of the battery stack 10) was measured. For the measurement, a digital microscope VHX-700 manufactured by Keyence Corporation was used. Then, a quadratic approximation equation was calculated for the measured height profile. From this approximation equation, the curvature at each position was calculated according to the following equation. curvature=|d 2 y / dx 2 | / {1+(dy / dx) 2} 3 / 2 Here, x represents the height of the current collector surface, and y represents the position.

[0092] The results are shown in Figures 6 and 7. Figure 6 is a graph showing the height profile and curvature distribution for the all-solid-state battery sample of the Example. Figure 7 is a graph showing the height profile and curvature distribution for the all-solid-state battery sample of the Comparative Example.

[0093] 6 and 7, it can be seen that a nearly constant curvature is obtained within the current collector plane in both the all-solid-state battery samples of the Examples and Comparative Examples. The curvatures are as follows: Curvature (mm -1 ) Example: 0.00014 Comparative Example 0.007

[0094] From this, it was confirmed that warpage was very small in the all-solid-state battery sample of Example 1 compared to the comparative example. Moreover, it was confirmed that warpage was also very small in the all-solid-state battery samples of Examples 2 and 3, and that the misalignment of the layers of the battery stack was suppressed compared to the all-solid-state battery sample of Example 1, making it easier to avoid short circuits between the end faces of the positive electrode body and the negative electrode body that constitute the battery stack.

[0095] From the above results, the effectiveness of the manufacturing method for the all-solid-state battery according to the present disclosure was confirmed. [Explanation of symbols]

[0096] 10 Battery stack 20 Laminated film container 30 Inclusion bodies 40, 40a, 40b, 40c, 40d support plate 42 Through hole 45 Auxiliary support plate 50 Elastic Clips 55 Elastic Body 60 Pressure Vessels 70 Volts 72 Nut 100 Positive electrode current collector 102 Positive electrode current collecting tab 110 Cathode active material layer 120 Positive electrode layer 200 Negative electrode current collector 202 Negative electrode current collecting tab 210 Negative electrode active material layer 220 Negative electrode layer 310 First solid electrolyte layer 320 Second solid electrolyte layer 330 Circumference 400 Insulation Layer 500 Positioning fixture 520a, 520b butt

Claims

1. encapsulating the battery stack within a laminate film container to obtain an encapsulation; Laminating support plates on both outer surfaces of the enclosure and sandwiching the enclosure between the support plates; and applying isotropic pressure to the inclusion body while the inclusion body and the support plate are in contact with each other to compress the inclusion body; and The magnitude of the isotropic pressure is 10 MPa or more. How solid-state batteries are manufactured.

2. The method for producing an all-solid-state battery according to claim 1 , wherein the support plate is clamped by an elastic clip, so that the enclosure and the support plate are brought into contact with each other by a repulsive force of the elastic clip.

3. 2. The method for producing an all-solid-state battery according to claim 1, wherein an auxiliary support plate is further laminated via an elastic body on at least one of the outer surfaces of the support plate that sandwiches the encapsulation body, thereby bringing the encapsulation body and the support plate into contact with each other by a repulsive force of the elastic body.

4. 3. The method for producing an all-solid-state battery according to claim 1, wherein the isotropic pressure is applied in a pressure vessel, and the encapsulated body sandwiched between the support plates is disposed in the pressure vessel such that a stacking surface of the battery stack is non-horizontal.

5. forming a positive electrode active material layer on one or both sides of a positive electrode current collector to prepare a positive electrode layer; forming a negative electrode active material layer on one or both sides of a negative electrode current collector to prepare a negative electrode layer; Providing a first solid electrolyte layer and a second solid electrolyte layer; and preparing the battery stack by contacting the positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer via the first solid electrolyte layer, and disposing a second solid electrolyte layer on at least one of an end face of the positive electrode layer and an end face of the negative electrode layer; Including, When preparing the battery stack, an insulating layer is provided on the outer periphery of the second solid electrolyte layer, and end faces of the layers of the battery stack are aligned at at least two points on the outer periphery of the battery stack, thereby positioning the layers in the stacking direction. The method for producing the all-solid-state battery according to claim 1 or 2.

6. forming a positive electrode active material layer on one or both sides of a positive electrode current collector to prepare a positive electrode layer; forming a negative electrode active material layer on one or both sides of a negative electrode current collector to prepare a negative electrode layer; Providing a first solid electrolyte layer; and preparing the battery stack by contacting the positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer via the first solid electrolyte layer; Including, When preparing the battery stack, an insulating layer is provided on the outer periphery of the first solid electrolyte layer, and end faces of the layers of the battery stack are aligned at at least two points on the outer periphery of the battery stack, thereby positioning the layers in the stacking direction. The method for producing the all-solid-state battery according to claim 1 or 2.

7. forming a positive electrode active material layer on one or both sides of a positive electrode current collector to prepare a positive electrode layer; forming a negative electrode active material layer on one or both sides of a negative electrode current collector to prepare a negative electrode layer; Providing a first solid electrolyte layer and a second solid electrolyte layer; and preparing a battery stack by contacting the positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer via the first solid electrolyte layer, and disposing a second solid electrolyte layer on at least one of an end face of the positive electrode layer and an end face of the negative electrode layer; Including, when preparing the battery stack, an insulating layer is provided on the outer periphery of the second solid electrolyte layer, and the outer shapes of the end faces of each layer exposed to the outer shape of the battery stack are made substantially the same, and the end faces of each layer of the battery stack are aligned over the entire outer periphery of the battery stack, thereby positioning the layers in the stacking direction. How solid-state batteries are manufactured.

8. forming a positive electrode active material layer on one or both sides of a positive electrode current collector to prepare a positive electrode layer; forming a negative electrode active material layer on one or both sides of a negative electrode current collector to prepare a negative electrode layer; Providing a first solid electrolyte layer; and preparing a battery stack by contacting the positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer via the first solid electrolyte layer; Including, when preparing the battery stack, an insulating layer is provided on the outer periphery of the first solid electrolyte layer, and the outer shapes of the end faces of each layer exposed to the outer shape of the battery stack are made substantially the same, and the end faces of each layer of the battery stack are aligned over the entire outer periphery of the battery stack, thereby positioning the layers in the stacking direction. How solid-state batteries are manufactured.

9. The method for producing an all-solid-state battery according to claim 7 or 8, further comprising applying an isostatic pressure to the battery stack.

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