JP2023008961A - Manufacturing method of all-solid battery - Google Patents

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

The present disclosure relates to a method for manufacturing an all-solid-state battery. The present disclosure particularly relates to a method for manufacturing a stacked all-solid-state battery.

Lithium ion batteries are used as batteries that are small and have high energy density. Among lithium-ion batteries, all-solid-state batteries in which the electrolytic solution is replaced with a solid electrolyte are attracting particular attention. This is because the all-solid-state battery uses a solid electrolyte instead of a conventional electrolytic solution, and is expected to further increase the energy density.

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 laminate. . In an all-solid-state battery, lithium ions move between each layer of the battery stack. In order to increase the transfer efficiency of lithium ions, it is necessary to increase the adhesion between each layer. Therefore, in the production of all-solid-state batteries, it is common practice to compress the battery stack using a press machine and/or a roll press machine. In recent years, the use of isostatic pressure application has been studied in order to further improve the adhesion between the layers of the battery stack.

For example, Patent Literature 1 discloses a method for manufacturing an all-solid-state battery including applying an isotropic pressure to a battery stack.

JP 2019-121558 A

In the method for manufacturing an all-solid-state battery disclosed in Patent Document 1 (hereinafter simply referred to as “the manufacturing method of Patent Document 1”), a support plate is laminated on one surface of a battery stack, and isotropic pressure is applied to this. is disclosed to be applied. Further, Patent Document 1 discloses enclosing a battery stack and a support plate together in a laminate film container when isotropic pressure is applied.

In the manufacturing method of Patent Document 1, it is necessary to open the laminate film container after applying the isotropic pressure and take out the battery stack and the support plate, and the productivity is not high. In addition, a large amount of waste from laminated film containers is generated, causing an increase in manufacturing costs. In the case where the battery stack and the support plate were not enclosed together in the laminate film container, the support plate sometimes shifted when the isotropic pressure was applied. Moreover, when the support plate was not used, the battery stack was warped after the isotropic pressure was applied. When the battery stack is prepared, the end surfaces of the layers of the battery stack are likely to be misaligned, and the end surfaces of the positive electrode and the negative electrode constituting the battery stack may be short-circuited.

For these reasons, the inventors of the present invention have found a need for a method for manufacturing an all-solid-state battery that can suppress the warping of the battery stack and efficiently enhance the adhesion between the layers of the battery stack. Found it. Further, when preparing the battery stack, it is possible to suppress the displacement of each layer of the battery stack, and to avoid a short circuit between the end surface of the positive electrode body and the end surface of the negative electrode constituting the battery stack. The present inventors have found the problem that there is a demand for a manufacturing method of

The present disclosure has been made to solve the above problems. That is, an object of the present disclosure is to provide a method for manufacturing an all-solid-state battery that can suppress warping of a battery stack and efficiently enhance adhesion between layers of the battery stack. Further, the present invention provides a method for manufacturing an all-solid-state battery that can suppress the displacement of each layer of the battery stack when preparing the battery stack, and can avoid short-circuiting between the end faces of the positive electrode body and the end face of the negative electrode body. for the purpose.

In order to achieve the above object, the present inventors have made intensive studies and completed a method for manufacturing an all-solid-state battery according to the present disclosure. A method for manufacturing an all-solid-state battery of the present disclosure includes the following aspects.
<1> enclosing the battery laminate in a laminate film container to obtain an enclosure;
Laminating support plates on both outer surfaces of the enclosure, and sandwiching the enclosure with the support plates;
compressing the enclosure by applying an isotropic pressure to the enclosure while bringing the enclosure and the support plate into contact;
including,
A method for manufacturing an all-solid-state battery.
<2> The method of manufacturing an all-solid-state battery according to <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 the repulsive force of the elastic clip.
<3> By further laminating an auxiliary support plate via an elastic body on at least one of the outer surfaces of the support plate sandwiching the enclosure, the enclosure and the support are separated by the repulsive force of the elastic body. The method for manufacturing an all-solid-state battery according to <1>, wherein the plates are brought into contact.
<4> The isotropic pressure is applied in a pressure vessel, and the enclosure sandwiched between the support plates is arranged in the pressure vessel such that the stacking surface of the battery stack is non-horizontal. The method for manufacturing an all-solid-state battery according to any one of <1> to <3>.
<5> preparing a positive electrode layer by forming a positive electrode active material layer on one or both sides of a positive electrode current collector;
preparing a negative electrode layer by forming a negative electrode active material layer on one or both sides of a negative electrode current collector;
providing a first solid electrolyte layer and a second solid electrolyte layer; and
The positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer are in contact with each other through the first solid electrolyte layer, and at least the end surface of the positive electrode layer and the end surface of the negative electrode layer Arranging a second solid electrolyte layer in either to prepare the battery stack;
When preparing the battery stack, an insulating layer is placed on the outer periphery of the second solid electrolyte layer, and the end faces of each layer of the battery stack are aligned at least at two locations on the outer periphery of the battery stack. Positioning in the stacking direction is performed by
A method for manufacturing an all-solid-state battery according to any one of <1> to <4>.
<6> preparing a positive electrode layer by forming a positive electrode active material layer on one or both sides of a positive electrode current collector;
preparing a negative electrode layer by forming a negative electrode active material layer on one or both sides of a negative electrode current collector;
providing a first solid electrolyte layer; and
preparing the battery stack by bringing the positive electrode active material layer of the positive electrode layer into contact with the negative electrode active material layer of the negative electrode layer through the first solid electrolyte layer;
When preparing the battery stack, an insulating layer is placed on the outer periphery of the first solid electrolyte layer, and the end faces of each layer of the battery stack are aligned at least at two locations on the outer periphery of the battery stack. Positioning in the stacking direction is performed by
A method for manufacturing an all-solid-state battery according to any one of <1> to <4>.
<7> preparing a positive electrode layer by forming a positive electrode active material layer on one or both sides of a positive electrode current collector;
preparing a negative electrode layer by forming a negative electrode active material layer on one or both sides of a negative electrode current collector;
providing a first solid electrolyte layer and a second solid electrolyte layer; and
The positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer are in contact with each other through the first solid electrolyte layer, and at least the end surface of the positive electrode layer and the end surface of the negative electrode layer Arranging a second solid electrolyte layer on either to prepare a battery stack;
When preparing the battery stack, an insulating layer is placed on the outer periphery of the second solid electrolyte layer, and the end faces of each layer of the battery stack are aligned at least at two locations on the outer periphery of the battery stack. Positioning in the stacking direction is performed by
A method for manufacturing an all-solid-state battery.
<8> preparing a positive electrode layer by forming a positive electrode active material layer on one or both sides of a positive electrode current collector;
preparing a negative electrode layer by forming a negative electrode active material layer on one or both sides of a negative electrode current collector;
providing a first solid electrolyte layer; and
preparing a battery laminate by bringing the positive electrode active material layer of the positive electrode layer into contact with the negative electrode active material layer of the negative electrode layer through the first solid electrolyte layer;
When preparing the battery stack, an insulating layer is placed on the outer periphery of the first solid electrolyte layer, and the end faces of each layer of the battery stack are aligned at least at two locations on the outer periphery of the battery stack. Positioning in the stacking direction is performed by
A method for manufacturing an all-solid-state battery.
<9> The method for producing an all-solid-state battery according to <7> or <8>, wherein an isotropic pressure is applied to the battery stack.

According to the present disclosure, when isotropic pressure is applied to the enclosure, in order to follow the compression of the enclosure and maintain the contact between the enclosure and the support plate, the warp of the battery stack after the application of the isotropic pressure can be suppressed. Further, since the outer surface of the enclosure is sandwiched by the support plates, it is not necessary to remove the support plates from the laminate film container after the isotropic pressure is applied. From these, according to the present disclosure, it is possible to provide a method for manufacturing an all-solid-state battery that can suppress the warping of the battery stack and efficiently enhance the adhesion between the layers of the battery stack. Then, by arranging the insulating layer at a predetermined position and positioning the stacking direction at a predetermined position to prepare the battery stack, the shift of each layer of the battery stack is suppressed, and the end surface of the positive electrode and the end surface of the negative electrode are prevented. It is possible to provide a method for manufacturing an all-solid-state battery that can avoid a short circuit with.

FIG. 1 is an explanatory diagram schematically showing an example of an embodiment of a method for manufacturing an all-solid-state battery of the present disclosure. FIG. 2 is an explanatory diagram schematically showing another example of an embodiment of the method for manufacturing an all-solid-state battery of the present disclosure. FIG. 3 is an explanatory diagram schematically showing a cross section of a state in which the enclosure is sandwiched between the support plate and the auxiliary support plate from the state of FIG. FIG. 4 is an explanatory diagram schematically showing one aspect of applying an isostatic pressure within a pressure vessel in the method for manufacturing an all-solid-state battery of the present disclosure. FIG. 5 is an explanatory diagram schematically showing another aspect of applying an isostatic pressure within the pressure vessel in the method for manufacturing an all-solid-state battery of the present disclosure. FIG. 6 is a graph showing the height profile and curvature distribution of the all-solid-state battery sample of the example. FIG. 7 is a graph showing the height profile and curvature distribution of the all-solid-state battery sample of the comparative example. FIG. 8 is an explanatory diagram schematically showing an example of a conventional method for manufacturing an all-solid-state battery. FIG. 9 is an explanatory diagram schematically showing another example of a conventional method for manufacturing an all-solid-state battery. FIG. 10A is a schematic cross-sectional view of an example of a method of forming a positive electrode active material layer on both sides of a positive electrode current collector and forming a negative electrode active material layer on both sides of a negative electrode current collector to obtain a battery laminate. 3 is an explanatory diagram shown in FIG. FIG. 10B is an explanatory view schematically showing a cross section of the battery stack obtained by the method shown in FIG. 10A. FIG. 11A is a schematic cross-sectional view of an example of a method of forming a positive electrode active material layer on one side of a positive electrode current collector and forming a negative electrode active material layer on both sides of a negative electrode current collector to obtain a battery laminate. 3 is an explanatory diagram shown in FIG. FIG. 11B is an explanatory view schematically showing the cross section of the battery stack obtained by the method shown in FIG. 11A. FIG. 12A is an explanatory view schematically showing the top surface of an example of the positive electrode layer used in the method shown in FIG. 10A. FIG. 12B is an explanatory view schematically showing the top surface of an example of the negative electrode layer used in the method shown in FIG. 10A. FIG. 12C is an explanatory view schematically showing the upper surface of an example of the first solid electrolyte layer used in the method shown in FIG. 10A. FIG. 12D is an explanatory diagram schematically showing the upper surface of an example of the insulating layer used in the method shown in FIG. 10A. 12E is an illustration showing the upper surface 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; It is a diagram. FIG. 13 is an explanatory diagram showing the top surface of another aspect of the positioning method. FIG. 14 is an explanatory diagram showing the top surface of still another aspect of the positioning method. FIG. 15 is an explanatory view showing a cross section of a method of forming the second solid electrolyte layer, which is different from the case of FIG. 10A. FIG. 16 is an explanatory diagram showing a cross section of an example of a mode in which the second solid electrolyte layer is omitted.

Hereinafter, embodiments of the method for manufacturing an all-solid-state battery of the present disclosure will be described in detail. It should be noted that the embodiments shown below do not limit the manufacturing method of the all-solid-state battery of the present disclosure.

Although not bound by theory, the manufacturing method of the all-solid-state battery of the present disclosure (hereinafter sometimes referred to as the “manufacturing method of the present disclosure”) suppresses the warping of the battery stack, The reason why the adhesion can be efficiently improved will be described with reference to the drawings.

The isotropic pressure is applied by applying a high pressure medium to the object. Therefore, when isotropic pressure is applied to a battery stack as an object, it is necessary to avoid damage or contamination of the battery stack by the pressure medium. For this reason, the battery stack is enclosed in a laminate film container, and an isotropic pressure is applied to the enclosure.

When the battery stack is enclosed in a laminate film container and an isotropic pressure is applied as it is, the battery stack is warped. Therefore, by attaching a support plate to the battery stack and applying an isotropic pressure, it is possible to suppress warping of the battery stack.

FIG. 8 is an explanatory diagram schematically showing an example of a conventional method for manufacturing an all-solid-state battery, and FIG. 9 is an explanatory diagram schematically showing another example of a conventional method for manufacturing an all-solid-state battery.

When isotropic pressure is applied to the battery stack with the support plate attached, it is necessary to prevent the battery stack from separating from the support plate. Therefore, in the prior art, for example, the manufacturing method of Patent Document 1, as shown in FIG. In the example shown in FIG. 8, the battery laminate 10 is enclosed in a laminate film container 20, the enclosure 30 is attached with a support plate 40, and further enclosed in the laminate film container 20 to form the enclosure 30. Separation of the support plate 40 is avoided. From the viewpoint of avoiding separation of the battery stack 10 and the support plate 40, the support plate 40 may be directly attached to the battery stack 10 as shown in FIG. In the prior art, in any case, as shown in FIGS. 8 and 9, it was necessary to enclose the battery stack 10 or enclosure 30 and the support plate 40 together in the laminate film container 20 . Since the support plate 40 is not required 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 applying the isotropic pressure.

Accordingly, the inventors have found the following. This knowledge will be described with reference to the drawings. FIG. 1 is an explanatory diagram schematically showing an example of an embodiment of a method for manufacturing an all-solid-state battery of the present disclosure.

In the manufacturing method of the all-solid-state battery of the present disclosure, for example, as shown in FIG. . An isotropic pressure is applied to the enclosure 30 sandwiched between the support plates 40 so that the enclosure 30 and the support plate 40 are kept in contact even when the enclosure 30 is compressed. For this purpose, pressure is applied to the support plate 40 separately from the application of the isotropic pressure so that the contact between the enclosure 30 and the support plate 40 is maintained. Specifically, for example, in the embodiment shown in FIG. 1, the enclosure 30 sandwiched by the support plate 40 is further sandwiched by the elastic clip 50 . As a result, isotropic pressure is applied to the enclosure 30 to compress the enclosure 30 while the enclosure 30 and the support plate 40 are in contact with each other.

When the enclosure 30 held by the support plate 40 is further held by the elastic clip 50 , a slight pressure can be applied to the enclosure 30 via the support plate 40 by the elastic clip 50 . However, the battery stack 10 in the enclosure 30 is hardly compressed only by the pressure applied by the elastic clip 50, and as a result, the layers in the battery stack 10 cannot be brought into close contact with each other. Therefore, when isotropic pressure is applied to the enclosure 30 and the support plate 40 while they are held between the elastic clips 50, 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 support plate 40 is held between the elastic clips 50, the two holding portions of the elastic clips 50 are separated from each other, and a repulsive force acts on the support plate 40 to narrow the separation. ing. Due to this repulsive force, the contact between the enclosure 30 and the support plate 40 can be maintained even if the enclosure 30 is compressed when the isotropic pressure is applied. That is, it is possible to compress the enclosure 30 by applying an isotropic pressure to the enclosure 30 while bringing the enclosure 30 and the support plate 40 into contact with each other.

By applying isotropic pressure to the enclosure 30 while the enclosure 30 and the support plate 40 are in contact with each other in this manner, the support plate 40 may separate from the enclosure 30 during application of the isotropic pressure, The inventors have found that they do not shift. As a result, 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, the enclosure 30 and the support plate 40 are separated. Separation and/or slippage can be avoided. Therefore, it is not necessary to remove the support plate 40 from the laminate film container 20 after the isotropic pressure is applied, as in the manufacturing method of Patent Document 1. That is, 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, warping of the battery stack 10 can be efficiently avoided. or can be suppressed, the inventors have found.

The constituent requirements of the method for manufacturing an all-solid-state battery according to the present disclosure, which have been completed based on the knowledge and the like described so far, will be described below.

<<Manufacturing method of all-solid-state battery>>
A method for manufacturing an all-solid-state battery of the present disclosure includes an enclosure preparation step, an enclosure sandwiching step, and an isotropic pressure application step. Each of these will be described below.

<Inclusion body preparation process>
First, an inclusion body is prepared. Specifically, the battery laminate is enclosed in a laminate film container to obtain an enclosure.

Known battery stacks for use in the manufacture of all-solid-state batteries can be selected. A preferred method for forming the battery stack will be described in detail later in "<Battery Stack Preparing Step>". Such a battery stack is obtained by stacking one or more unit cells. A unit battery can typically be obtained by laminating 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. At this time, a well-known negative electrode current collector, negative electrode active material layer, solid electrolyte layer, positive electrode active material layer, and positive electrode current collector for all-solid-state batteries can be selected. Each of these will be described below, but the present invention is not limited to this.

Negative Electrode Current Collector For example, Ag, Cu, Au, Al, Ni, Fe, stainless steel, Ti, or an alloy thereof can be used as the material for the negative electrode current collector. 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.

- 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. As the negative electrode active material, a well-known material having the function of a negative electrode active material for all-solid-state batteries can be selected, and there is no particular limitation. The negative electrode active material can be selected from materials capable of intercalating and deintercalating metal ions such as lithium ions. The negative electrode active material can be selected from, for example, carbon materials such as metallic lithium, lithium alloys, graphite or hard carbon, silicon materials such as metallic silicon and silicon alloys, Li ₄ Ti ₅ O ₁₂ (LTO), and the like. . A combination of these materials may be 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 also be selected from other metallic materials such as indium, aluminum, or tin, or combinations 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 coated with an amorphous coating.

Solid electrolytes include sulfide-based amorphous solid electrolytes such as Li ₂ SP ₂ S ₅ , Li ₂ O.Li _{2 S.P 2 S 5 , Li 2 S , P 2} S ₅ and Li ₂ S. -SiS ₂ , LiI-Li ₂ S-SiS ₂ , LiI-Li ₂ SP ₂ S ₅ , LiI-Li ₂ SP ₂ O ₅ , LiI-LiBr-Li ₂ SP ₂ S ₅ , LiI- Li ₃ PO ₄ —P ₂ S ₅ or the like; or oxide-based amorphous solid electrolytes such as Li ₂ O—B ₂ O ₃ —P ₂ O _5, Li ₂ O—SiO ₂ or the like; or oxides crystalline solid electrolytes, such as LiI, Li ₃ N, Li ₅ La ₃ Ta ₂ O ₁₂ , Li ₇ Zr ₂ O ₁₂ , Li ₆ BaLa ₂ Ta ₂ O ₁₂ , Li ₃ PO _(4-3/2w) N _w (w<1), etc.; or sulfide _- based crystalline solid electrolytes such as glass _ceramics such _{as Li7P3S11 , Li3.25P0.75S4 ,} or _{Li3.24P0.75S4 .} Thio-LiSiO-based crystals such as ₂₄ Ge _0.76 S ₄ and those having an aldirodite-type crystal structure such as Li ₆ PS ₅ X (X=Cl, Br) (hereinafter referred to as “aldirodite-type sulfide solid electrolytes”) etc.; or a combination thereof. Aldirodite-type sulfide solid electrolytes are preferred from the viewpoint of high lithium ion conductivity and electrochemical stability.

There are no particular restrictions on the binder as long as it does not adversely affect the performance and production 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. mentioned. A combination of these may be selected. Polyolefin resins include styrene-butadiene rubber (SBR), polypropylene (PP), polyethylene (PE), polymethyl methacrylate (PMMA), polymethyl acrylate, polybutyl acrylate (PBA), polyacrylonitrile (PAN), and the like. (Meth)acrylic resins and the like. A combination of these may be selected.

The negative electrode active material layer may further optionally contain, for example, a binder solvent and a conductive material.

A solvent for the binder is not particularly limited as long as it does not adversely affect the performance and production of the all-solid-state battery. Solvents for the binder include, for example, butyl butyrate, toluene, and methyl ethyl ketone (MEK), and mixed solvents thereof may also be used.

The conductive material can be selected from carbon materials such as VGCF (Vapor Grown Carbon Fiber), acetylene black, ketjen black, carbon nanotubes, or combinations thereof.

- Solid electrolyte layer The solid electrolyte layer contains at least a solid electrolyte, and may optionally contain a binder or the like. Examples of solid electrolytes used for the solid electrolyte layer include the solid electrolytes described in the section “.negative electrode active material layer”.

Examples of binders include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), butylene rubber (BR), styrene-butadiene rubber (SBR), polyvinyl butyral (PVB), and acrylic resins. These may be used in combination. As a solvent for these binders, for example, heptane or the like may be used.

- Positive electrode 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. As the positive electrode active material, at least one transition metal selected from manganese, cobalt, nickel and titanium, and a metal oxide containing lithium, such as lithium cobaltate, lithium nickelate, lithium manganate, nickel cobalt lithium manganate, etc. , dissimilar element-substituted Li—Mn spinel, lithium titanate, lithium metal phosphate, or combinations thereof.

As for the conductive material, the conductive material described in the section “.Negative electrode active material layer” can be used. As for the solid electrolyte, the solid electrolyte described in “.Negative electrode active material layer” can be used. Further, as the binder and its solvent, the binder and its solvent described in the section “.solid electrolyte layer” can be used.

- Positive electrode current collector For the positive electrode current collector, the negative electrode current collector described in the section "Negative electrode current collector" can be referred to. Among them, aluminum is preferable as the positive electrode current collector from the viewpoint of chemical stability.

- Formation method of battery laminate As a method of formation of the battery laminate, a well-known method can be applied in the production of all-solid-state batteries. A typical method for forming a battery stack will be briefly described below, but the present invention is not limited to this.

A unit battery is formed 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. There is no particular limitation on the lamination method. For example, a solid electrolyte layer is formed on the surface of the base plate, and the solid electrolyte layer side is attached to one of the negative electrode active material layer and the positive electrode active material layer. After that, 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 attached to the surface of the solid electrolyte layer. A negative electrode current collector and a positive electrode current collector are attached in advance to one side of each of the negative electrode active material layer and the positive electrode active material layer, and the solid electrolyte layer has the negative electrode current collector and the positive electrode current collector attached thereto. Attach the unattached sides.

A unit battery may be used as a battery stack, or a unit battery may be stacked and used as a battery stack. After the formation of the unit cells and/or after the stacking of the unit cells, the unit cells and/or the stack of unit cells may optionally be pressed in advance using a roll press or the like. As described above, it is necessary to apply isotropic pressure in order to improve the adhesion between the layers of the battery laminate. In this case, it is possible to suppress damage or the like of the battery stack.

The formation of the negative electrode active material layer, the solid electrolyte layer, and the positive electrode active material layer can apply a well-known method for manufacturing an all-solid-state battery. These typical formation methods will be briefly described below, but are not limited to these.

As a method for forming the negative electrode active material layer, a negative electrode mixture paste containing a negative electrode active material and optionally a solid electrolyte and a binder is prepared, the negative electrode mixture paste is applied to the surface of the negative electrode current collector, and dried. Let The negative electrode mixture paste may further optionally contain a binder solvent, a conductive material, and the like. The method of applying the negative electrode mixture is not particularly limited, and examples thereof include a doctor blade method, a metal mask printing method, an electrostatic coating method, a dip coating method, a spray coating method, a roll coating method, a gravure coating method, and a screen printing method. is mentioned. These may be used in combination.

Examples of the method for forming the solid electrolyte layer include a method of compression-molding a powder, pellet, or the like of a solid electrolyte layer-forming raw material containing at least a solid electrolyte. Alternatively, a method of applying a raw material paste for forming a solid electrolyte layer containing at least a solid electrolyte and a solvent onto the surface of the base plate and drying the paste may be used. The raw material for solid electrolyte layer formation and the raw material paste for solid electrolyte layer formation may optionally contain a binder or the like.

As a method for forming the positive electrode active material layer, a positive electrode mixture paste containing at least a positive electrode active material is prepared, the positive electrode mixture paste is applied to the surface of a positive electrode current collector, and dried. The positive electrode mixture paste may optionally contain a conductive material, a binder, and a solid electrolyte. The method of applying the positive electrode mixture paste to the surface of the positive electrode current collector can refer to the method of applying the negative electrode mixture paste to the surface of the negative electrode current collector.

The battery laminate obtained as described above is enclosed in a laminate film container to obtain an enclosure. This will be explained, for example, in the embodiment shown in FIG.

The laminate film container is not particularly limited as long as an isotropic pressure can be applied to the battery stack enclosed in the laminate film container. Typically, a well-known laminate film container used in all-solid-state batteries can be used, but the container is not limited to this. Typical examples include aluminum laminate film containers and the like.

<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 is explained, for example, in the embodiment shown in FIG. Support plates 40 are laminated on the outer surfaces of both sides of the enclosure 30 , and the enclosure 30 is sandwiched between the support plates 40 . The battery laminate 10 is formed by laminating 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. Here, in the embodiment shown in FIG. 1, 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 each laminated substantially horizontally. "Lamination of support plates on both outer surfaces of the enclosure" means that support plates are laminated 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. means to In other words, "support plates are laminated on both outer surfaces of the enclosure and the enclosure is held between the support plates" means that, for example, in the embodiment shown in FIG. means that Therefore, in the embodiment shown in FIG. 1, it means that the long sides (horizontal sides) of the enclosure 30 are sandwiched between the support plates 40. It does not mean to clamp at 40.

There is no particular limitation on the support plate 40 as long as the support plate 40 does not bend or deform in the isotropic pressure applying process described later. The support plate 40 preferably has excellent corrosion resistance against a pressure medium for isotropic pressure application. From this point of view, the support plate 40 is preferably made of, for example, aluminum, aluminum alloy, stainless steel, combinations thereof, and the like. Also, isostatic pressure is typically applied within the 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 isotropic pressure is applied. When the thin support plate 40 is used, a large number of enclosures 30 sandwiched by the support plate 40 can be loaded into the pressure vessel. From this point of view, the support plate 40 is preferably made of stainless steel, for example.

The thickness of the support plate 40 may be appropriately determined according to the relationship between the material type, 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.

<Isotropic pressure application process>
An isotropic pressure is applied to the enclosure while the enclosure and the support plate are in contact with each other to compress the enclosure. As described above, for example, in the embodiment shown in FIG. 1, the contact between the enclosure and the support plate is maintained by the elastic clip 50 when the isotropic pressure is applied, but the present invention is not limited to this. When the enclosing body and the support plate are kept in contact with each other, the repulsive force of the elastic clip 50 is applied to the support plate 40 in addition to the application of the isotropic force. Such a repulsive force may be of a level capable of maintaining contact between the enclosure and the support plate. .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, by the repulsive force of the elastic clip 50, pressure is applied to the support plate 40 separately from the application of the isotropic pressure, and the contact between the enclosure 30 and the support plate 40 is maintained.

Here, an embodiment different from that of FIG. 1 will be described. FIG. 2 is an explanatory diagram schematically showing another example of an embodiment of the method for manufacturing an all-solid-state battery of the present disclosure. FIG. 3 is an explanatory diagram schematically showing a cross section of the enclosure 30 sandwiched between the support plates 40a, 40b, 40c, and 40d and the auxiliary support plate 45 from the state of FIG.

As shown in FIG. 3, an auxiliary support plate 45 is further laminated via an elastic member 55 on the outer surfaces of the support plates 40a, 40b, 40c, and 40d that sandwich the enclosure 30. As shown in FIG. As a result, the contact between the support plates 40a, 40b, 40c, and 40d and the enclosure 30 is maintained by the repulsive force (biasing force) of the elastic body 55 while the isotropic pressure is being applied. The repulsive force (biasing force) of the elastic body is sufficient as long as it can maintain the contact between the enclosure and the support plate. It may be 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, by the repulsive force (biasing force) of the elastic body 55, pressure is applied to the support plate 40 separately from the application of the isotropic pressure, and the contact between the enclosure 30 and the support plate is maintained. It should be noted that the enclosure 30 shown in FIG. 3 may be considered similar to the enclosure 30 already described. Also, in the embodiment shown in FIG. 3, the number of inclusion bodies 30 is three, but the number is not limited to this.

The battery laminate 10 in the enclosure 30 is formed by laminating 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. 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 each arranged (stacked) substantially horizontally. there is "Auxiliary support plate is laminated via an elastic body on at least one of the outer surfaces of the support plate that sandwiches the encapsulant" means the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, and the positive electrode active material. It means laminating the auxiliary support plate as well as the layer and the positive electrode current collector. Therefore, the phrase "an auxiliary support plate is laminated via an elastic body on at least one of the outer surfaces of the support plates that sandwich the enclosure" means, for example, the auxiliary support plate 45 in the embodiment shown in FIG. is substantially horizontal. In the embodiment shown in FIG. 3, "on at least one side" means that the auxiliary support plate is laminated via the elastic body 55 on the upper outer surface (upper surface of the support plate 40d) in FIG. However, it means that it is not limited to this. That is, the auxiliary support plate 45 may be laminated via the elastic body 55 on both the upper and lower outer surfaces (both the upper surface of the support plate 40d and the lower surface of the support plate 40a) in FIG. means

Since the auxiliary support plate 45 is laminated on the outer side surfaces of the support plates 40a, 40b, 40c, and 40d sandwiching the enclosure 30 via the elastic body 55, the repulsive force (biasing force) of the elastic body 55 occurs. However, the repulsive force of the elastic body 55 alone cannot compress the battery stack 10 in the enclosure 30, and the layers in the battery stack 10 cannot be brought into close contact with each other. Therefore, when 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, apart from the application of the isotropic pressure, the repulsive force of the elastic body 55 acts on the support plates 40a, 40b, 40c, and 40d. can be done. That is, an isotropic pressure can be applied to the enclosure 30 while the enclosure 30 and the support plate 40 are in contact with each other.

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 other than the support plate 40a farthest from the auxiliary support plate 45, Since 40c and 40d are movable plates, the elastic body 55 generates a repulsive force. That is, the repulsive force of the elastic body 55 moves the support plates 40b, 40c, and 40d other than the support plate 40a farthest from the auxiliary support plate 45 . Thereby, the contact between the enclosure 30 and the support plates 40a, 40b, 40c, and 40d can be maintained by the repulsive force of the elastic body 55 while the isotropic pressure is being applied.

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 the support plates 40b, 40c, and 40d other than the support plate 40a farthest from the auxiliary support plate 45 and the auxiliary support A through hole 42 is formed in the plate 45 and a bolt 70 is inserted through the through hole 42 . Then, the nut 72 is fastened on the surface of the auxiliary support plate 45 opposite to the support plates 40a, 40b, 40c, and 40d so that the elastic body 55 generates a repulsive force. By doing so, the auxiliary support plate 45 and the support plate 40a farthest from the auxiliary support plate 45 are used as fixed plates, and the support plates 40b, 40c other than the support plate 40a farthest from the auxiliary support plate 45, 40d can be a movable plate.

The magnitude of the isotropic pressure to be applied may be appropriately determined in consideration of the area of the stacking surface of the battery stack 10 and the like so that the respective layers of the battery stack 10 in the enclosure 30 are 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 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. you can

The temperature at which the isotropic pressure is applied may be appropriately determined so that the respective layers of the battery stack 10 in the enclosure 30 are sufficiently adhered to each other and the battery stack 10 is not degraded. The isotropic pressure application temperature may be, for example, 100° C. or higher, 120° C. or higher, 140° C. or higher, 160° C. or higher, 180° C. or higher, or 190° C. or higher, and 300° C. or lower, 280° C. or lower, 260° C. or lower. , 240° C. or lower, 220° C. or lower, or 200° C. or lower.

The application time of the isotropic pressure may be appropriately determined so that the respective layers of the battery stack 10 in the enclosure 30 are sufficiently adhered to each other. The isotropic pressure application time is typically 0.5 minutes or more, 1 minute or more, 3 minutes or more, or 5 minutes or more, and is 60 minutes or less, 30 minutes or less, or 10 minutes or less. you can

A well-known pressure medium can be used as the pressure medium for applying the isotropic pressure. Pressure media include gases, liquids, powders, combinations thereof, and the like. The pressure medium is typically liquid, more typically water, oil, and combinations thereof.

The isotropic pressure application method is not particularly limited, and a well-known application method can be applied. Typically, the object is loaded into a pressure vessel and an isostatic pressure is applied to the object within the pressure vessel. At this time, in the pressure vessel, the enclosure sandwiched between the support plates may be arranged such that the stacking surface of the battery stack is non-horizontal. This will be explained using the drawings. FIG. 4 is an explanatory diagram schematically showing one aspect of applying an isostatic pressure within a pressure vessel in the method for manufacturing an all-solid-state battery of the present disclosure. FIG. 5 is an explanatory diagram schematically showing another aspect of applying an isostatic pressure within the pressure vessel in the method for manufacturing an all-solid-state battery of the present disclosure.

FIG. 4 shows a state in which the enclosure 30 and the like of the embodiment shown in FIGS. Due to space limitations, descriptions of the enclosure 30, the elastic body 55, and the like are omitted. As shown in FIG. 4, the stacking plane of each layer of the battery stack 10 in the enclosure 30 is typically substantially horizontal, but the stacking plane is not limited to this and may be non-horizontal. For example, as shown in FIG. 5, the stacking plane of each layer of the battery stack 10 in the enclosure 30 may be substantially vertical. As in FIG. 4, FIG. 5 also omits illustration of the enclosure 30, the elastic body 55, and the like due to space limitations. Also, the embodiment shown in FIG. 5 is similar to the embodiment of FIG. 4 except that the support plate 40 and the auxiliary support plate 45 are rectangular.

In the manufacturing method of the all-solid-state battery of the present disclosure, contact between the enclosure 30 and the support plate 40 is maintained even during application of the isotropic pressure. Therefore, as in the embodiment shown in FIG. 5, even if the stacking surface is non-horizontal, the displacement of the enclosure 30 can be avoided or suppressed. Also, as in the embodiment shown in FIG. 5, even if the cross-sectional area of the charging port of the pressure vessel 60 (above the pressure vessel 60) is smaller than the area of the stacking surface of the battery stack 10 in the enclosure 30, , the enclosure 30 or the like can be loaded into the pressure vessel 60 by making the stacking surface vertical.

<Battery laminate preparation process>
A battery stack may be formed as follows. This will be described with reference to the drawings. FIG. 10A is a schematic cross-sectional view of an example of a method of forming a positive electrode active material layer on both sides of a positive electrode current collector and forming a negative electrode active material layer on both sides of a negative electrode current collector to obtain a battery laminate. 3 is an explanatory diagram shown in FIG. FIG. 10B is an explanatory view schematically showing a cross section of the battery stack obtained by the method shown in FIG. 10A. FIG. 11A is a schematic cross-sectional view of an example of obtaining a battery laminate by forming a positive electrode active material layer on one side of a positive electrode current collector and forming a negative electrode active material layer on both sides of a negative electrode current collector. 3 is an explanatory diagram shown in FIG. FIG. 11B is an explanatory view schematically showing the cross section of the battery stack obtained by the method shown in FIG. 11A.

As shown in FIG. 10A, the cathode active material layer 110 is formed on both sides of the cathode current collector 100 to prepare the cathode layer 120, and the anode active material layer 210 is formed on both sides of the anode current collector 200 to prepare the anode. Prepare layer 220 . Alternatively, as shown in FIG. 11A, the cathode active material layer 110 is formed on one side of the cathode current collector 100 to prepare the cathode layer 120, and the anode active material layer 210 is formed on both sides of the anode current collector 200. to prepare the negative electrode layer 220 . Then, the first solid electrolyte layer 310 and the second solid electrolyte layer 320 are prepared. As shown in FIG. 11A, when the cathode active material layer 110 is formed on one side of the cathode current collector 100 to prepare the cathode layer 120, the cathode current collectors 100 are brought into contact with each other to obtain the cathode layer 120. . When the negative electrode active material layer 210 is formed on one side of the negative electrode current collector 200 to prepare the negative electrode layer 220 , the negative electrode current collectors 200 are brought into contact with each other to obtain the negative electrode layer 220 . The materials and forming 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 described above. be.

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 through the first solid electrolyte layer 310, and , the second solid electrolyte layer is placed on the end face of the positive electrode layer 120 to prepare the battery stack 10 . In the embodiments of FIGS. 10A and 11A, the outer peripheral edge of the first solid electrolyte layer 310 is bent to form the second solid electrolyte layer 320, but this is not restrictive. Details will be described later.

When preparing the battery stack 10, as shown in FIGS. , positioning in the stacking direction (vertical direction in FIG. 10A and/or FIG. 11A). There is no particular limitation on the material forming the insulating layer 400 as long as the insulating layer 400 can insulate electrical conduction. Materials constituting the insulating layer 400 include, for example, glass, mica, and insulating resins. thermoplastic resins are preferred.

Positioning in the stacking direction is performed by aligning the end surfaces of the respective layers of the battery stack 10 at at least two locations on the outer circumference of the battery stack 10 . This will be described with reference to the drawings. FIG. 12A is an explanatory view schematically showing the top surface of an example of the positive electrode layer used in the method shown in FIG. 10A. FIG. 12B is an explanatory view schematically showing the top surface of an example of the negative electrode layer used in the method shown in FIG. 10A. FIG. 12C is an explanatory view schematically showing the upper surface of an example of the solid electrolyte layer used in the method shown in FIG. 10A. FIG. 12D is an explanatory diagram schematically showing the upper surface of an example of the insulating layer used in the method shown in FIG. 10A. 12E is an illustration showing the upper surface 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; It is a diagram.

As shown in FIG. 10A, the cathode layer 120 is prepared by forming the cathode active material layer 110 on both sides of the cathode current collector 100 . At this time, as shown in FIG. 12A, a part of the positive electrode current collector 100 protrudes as the positive electrode current collecting tab 102 . Similarly, as shown in FIG. 12B, a portion of the negative electrode current collector 200 protrudes as a negative electrode current collecting tab 202 . For simplicity of explanation, FIG. 10A shows a cross section at a site where the positive electrode current collecting tab 102 and the negative electrode current collecting tab 202 are not present.

When preparing the battery stack 10 shown in FIG. 10A , the positioning jig 500 of FIG. do. The end face of each layer of the battery stack 10 means the end face of each layer exposed to the outer shape of the battery stack 10 . In the embodiment shown in FIG. 10A , the end surfaces of the layers exposed on the outer shape of the battery stack 10 are the end surfaces 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 face of each layer exposed to the outer shape of the battery stack 10 may be simply referred to as "the end face of each layer".

In the embodiment shown in FIG. 12E, positioning around the entire perimeter of the battery stack, excluding positive and negative current collecting tabs 102 and 202 positioning at multiple locations). Therefore, in the embodiment shown in FIG. 12E , the edge surfaces of the layers exposed to the outer shape of the battery stack 10 are positioned in this way, except for the portions where the positive electrode current collecting tab 102 and the negative electrode current collecting tab 202 are installed. are made substantially the same.

In the manufacturing method of the all-solid-state battery of the present disclosure, the positioning method is limited to the aspect shown in FIG. Absent. 13 and 14 are explanatory diagrams showing the upper surface of another aspect of the positioning method. In the embodiment shown in FIG. 13, two abutments 520a and 520b are used, and by abutting the end faces of each layer against these abutments 520a and 520b, the portions of the end faces of each layer that are in contact with the abutments 520a and 520b are are aligned to position the stacking direction of each layer. The arrangement positions of the two abutments 520a and 520b are not limited to the locations shown in FIG. 13, and may be the positions shown in FIG. 14, for example. Also, the number of bumps is not limited to two. That is, in the method for manufacturing an all-solid-state battery according to the present disclosure, each layer may be positioned in the stacking direction by aligning the end faces of each layer at at least two locations on the outer circumference of the battery stack 10 . Positions to be positioned may be appropriately determined according to the outer shape of each layer.

When positioning is performed at two locations, the angle between one positioning surface (for example, the positioning surface of the abutment 520a) and the other positioning surface (for example, the positioning surface of the abutment 520b) is θ. At this time, θ is not 0° or 180° (see FIG. 13), but θ is greater than 0°, 10° or more, 20° or more, 30° or more, 40° or more, 50° or more, 60° or more, It may be 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 case of the embodiment shown in FIG. 14, θ is 90°. By setting θ to the preferred angle described above, it is possible to advantageously suppress the displacement of each layer of the battery stack 10 in both the vertical direction and the horizontal direction in FIG. 12E.

Thus, 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.

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

10A and 11A, the first solid electrolyte layer 310 is in contact with both surfaces of the positive electrode layer 120, and both the first solid electrolyte layers 310 are bent at their outer peripheral portions to form the second solid electrolyte layer 320. to form, but is not limited to. Another method of forming second solid electrolyte layer 320 will be described with reference to the drawings. FIG. 15 is an explanatory diagram showing a cross section of a method of forming the second solid electrolyte layer 320 that is different from the case of FIG. 10A.

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 it is, and the upper first solid electrolyte layer 310 is bent to form a second solid electrolyte layer. 320 is formed, and the insulating layer 400 is arranged around the outer periphery of the second solid electrolyte layer 320 .

In the embodiment shown in FIG. 11A, the positive electrode layer 120 is obtained by forming the positive electrode active material layer 110 on one side of the positive electrode current collector 100, and the negative electrode active material layer 210 is formed on both sides of the negative electrode current collector 200. Although the negative electrode layer 220 is obtained, it is not limited to this. For example, the cathode active material layer 110 may be formed on both sides of the cathode current collector 100 to obtain the cathode layer 120, and the anode active material layer 210 may be formed on one side of the anode current collector 200 to obtain the anode layer 220. good. Alternatively, the cathode active material layer 110 may be formed on one side of the cathode current collector 100 to obtain the cathode layer 120, and the anode active material layer 210 may be formed on one side of the anode current collector 200 to obtain the anode layer 220. good.

By using the second solid electrolyte layer 320 and disposing the insulating layer 400 around the outer periphery of the second solid electrolyte layer 320 and preparing the battery stack 10 as described above, the following can be achieved. That is, it is possible to prepare the battery stack 10 at high speed while suppressing deviations in the stacking direction of each layer, and to avoid short circuits at the ends of the positive electrode layer 120 and the negative electrode layer 220 . This is particularly advantageous when the positive electrode layer 120 has a smaller outer shape than the negative electrode layer 220 or when the negative electrode layer 220 has a smaller outer shape than the positive electrode layer 120 .

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 an example of a mode in which the second solid electrolyte layer is omitted.

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 surfaces of the layers of the battery stack 10 are aligned at least at two locations on the outer periphery of the battery stack 10, thereby positioning in the stacking direction. do. The end face of each layer of the battery stack 10 in this aspect is the end face of each of the positive electrode layer 120 , the negative electrode layer 220 and the insulating layer 400 . According to this aspect, it is possible to prepare the battery stack 10 at high speed while suppressing the deviation of the stacking direction of each layer, and it is possible to avoid a short circuit at the end of the positive electrode layer 120 and the end of the negative electrode layer 220. . This aspect 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.

Even if the isotropic pressure is applied to the battery stack prepared in the manner described in the <Battery Stack Preparing Step>, the adhesion between the layers of the battery stack can be efficiently increased.

<deformation>
In addition to what has been described so far, the method for manufacturing an 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 implemented simultaneously. Specifically, the clamping body of the embodiment shown in FIG. 1 and the clamping body of the embodiment shown in FIG. 3 may be charged into the same pressure vessel and isotropic pressure may be applied to them. In addition, the “clamped body” means the entire enclosure 30 clamped by the support plate 40 and the elastic clip 50 as in the embodiment shown in FIG. 1, for example. Alternatively, it means the entire enclosure 30 sandwiched between the support plate 40 and the auxiliary support plate 45 as in the embodiment shown in FIG.

Hereinafter, the manufacturing method of the all-solid-state battery of the present disclosure will be described more specifically with reference to examples and comparative examples. Note that the method for manufacturing an all-solid-state battery of the present disclosure is not limited to the conditions used in the following examples.

《Preparation of all-solid-state battery sample》
An all-solid battery sample was prepared in the following manner.

<Example 1>
An isostatic pressure was applied to the enclosure 30 according to the embodiment shown in FIG. The isostatic pressure was 980 MPa and the isostatic pressure application temperature was 190°C. As the battery stack 10 in the enclosure 30, 10 unit cells were stacked.

<Comparative example>
An isotropic pressure was applied to the enclosure 30 as it was. That is, an isotropic pressure was applied to the enclosure 30 without attaching the support plate 40 thereto. The conditions for applying isotropic pressure and the number of stacked unit cells were the same as in the example.

<Example 2>
An all-solid battery sample was prepared in the same manner as in Example 1, except that the battery stack was prepared in the manner shown in FIG. 10A.

<Example 3>
An all-solid battery sample was prepared in the same manner as in Example 1, except that the battery stack was prepared in the manner shown in FIG.

"evaluation"
After the isotropic pressure was applied, the battery laminate 10 was taken out from the laminate film container 20 of the enclosure 30, and the height profile of the current collector surface (laminated surface of the battery laminate 10) was measured. A digital microscope VHX-700 manufactured by Keyence Corporation was used for the measurement. Then, a second-order approximation formula was calculated for the measured height profile. From this approximation formula, the curvature at each position was calculated according to the following formula.
Curvature=|d ² y/dx ² |/{1+(dy/dx) ² } ^3/2
However, x represents the height of the current collector surface, and y represents the position.

The results are shown in FIGS. 6 and 7. FIG. FIG. 6 is a graph showing the height profile and curvature distribution of the all-solid-state battery sample of the example. FIG. 7 is a graph showing the height profile and curvature distribution of the all-solid-state battery sample of the comparative example.

From FIGS. 6 and 7, it can be understood that substantially constant curvature is obtained in the current collector plane in both the all-solid-state battery samples of Examples and Comparative Examples. Also, their curvatures are as follows.
Curvature (mm ^-1 )
Example 0.00014
Comparative example 0.007

From this, it was confirmed that the all-solid-state battery sample of Example 1 had a very small warp compared to the comparative example. In addition, the all-solid-state battery samples of Examples 2 and 3 also had very little warpage, and compared with the all-solid-state battery sample of Example 1, the displacement of each layer of the battery stack was suppressed. It was confirmed that the short circuit between the end face of the positive electrode body and the end face of the negative electrode body constituting the laminate can be more easily avoided.

From the above results, the effect of the method for manufacturing an all-solid-state battery according to the present disclosure could be confirmed.

REFERENCE SIGNS LIST 10 battery laminate 20 laminate film container 30 enclosure 40, 40a, 40b, 40c, 40d support plate 42 through hole 45 auxiliary support plate 50 elastic clip 55 elastic body 60 pressure vessel 70 bolt 72 nut 100 positive electrode current collector 102 positive electrode collector Current tab 110 Positive electrode active material layer 120 Positive electrode layer 200 Negative electrode collector 202 Negative electrode current collector tab 210 Negative electrode active material layer 220 Negative electrode layer 310 First solid electrolyte layer 320 Second solid electrolyte layer 330 Periphery 400 Insulating layer 500 Positioning jig 520a , 520b butt

Claims (9)

enclosing the battery laminate in a laminate film container to obtain an enclosure;
Laminating support plates on both outer surfaces of the enclosure, and sandwiching the enclosure with the support plates;
compressing the enclosure by applying an isotropic pressure to the enclosure while bringing the enclosure and the support plate into contact;
including,
A method for manufacturing an all-solid-state battery. 2. The method of manufacturing an all-solid-state battery according to claim 1, wherein the support plate is sandwiched by elastic clips so that the enclosure and the support plate are brought into contact with each other by the repulsive force of the elastic clips. By further laminating an auxiliary support plate via an elastic body on at least one of the outer surfaces of the support plate sandwiching the enclosure, the enclosure and the support plate are brought into contact with each other by the repulsive force of the elastic body. The method for manufacturing the all-solid-state battery according to claim 1, wherein the all-solid-state battery is brought into contact. The isotropic pressure is applied in a pressure vessel, and the enclosure sandwiched between the support plates is arranged in the pressure vessel such that the stacking surface of the battery stack is non-horizontal. Item 3. A method for manufacturing an all-solid-state battery according to Item 1 or 2. preparing a positive electrode layer by forming a positive electrode active material layer on one or both sides of a positive electrode current collector;
preparing a negative electrode layer by forming a negative electrode active material layer on one or both sides of a negative electrode current collector;
providing a first solid electrolyte layer and a second solid electrolyte layer; and
The positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer are in contact with each other through the first solid electrolyte layer, and at least the end surface of the positive electrode layer and the end surface of the negative electrode layer Arranging a second solid electrolyte layer in either to prepare the battery stack;
When preparing the battery stack, an insulating layer is placed on the outer periphery of the second solid electrolyte layer, and the end faces of each layer of the battery stack are aligned at least at two locations on the outer periphery of the battery stack. Positioning in the stacking direction is performed by
The manufacturing method of the all-solid-state battery according to claim 1 or 2. preparing a positive electrode layer by forming a positive electrode active material layer on one or both sides of a positive electrode current collector;
preparing a negative electrode layer by forming a negative electrode active material layer on one or both sides of a negative electrode current collector;
providing a first solid electrolyte layer; and
preparing the battery stack by bringing the positive electrode active material layer of the positive electrode layer into contact with the negative electrode active material layer of the negative electrode layer through the first solid electrolyte layer;
When preparing the battery stack, an insulating layer is placed on the outer periphery of the first solid electrolyte layer, and the end faces of each layer of the battery stack are aligned at least at two locations on the outer periphery of the battery stack. Positioning in the stacking direction is performed by
The manufacturing method of the all-solid-state battery according to claim 1 or 2. preparing a positive electrode layer by forming a positive electrode active material layer on one or both sides of a positive electrode current collector;
preparing a negative electrode layer by forming a negative electrode active material layer on one or both sides of a negative electrode current collector;
providing a first solid electrolyte layer and a second solid electrolyte layer; and
The positive electrode active material layer of the positive electrode layer and the negative electrode active material layer of the negative electrode layer are in contact with each other through the first solid electrolyte layer, and at least the end surface of the positive electrode layer and the end surface of the negative electrode layer Arranging a second solid electrolyte layer on either to prepare a battery stack;
When preparing the battery stack, an insulating layer is placed on the outer periphery of the second solid electrolyte layer, and the end faces of each layer of the battery stack are aligned at least at two locations on the outer periphery of the battery stack. Positioning in the stacking direction is performed by
A method for manufacturing an all-solid-state battery. preparing a positive electrode layer by forming a positive electrode active material layer on one or both sides of a positive electrode current collector;
preparing a negative electrode layer by forming a negative electrode active material layer on one or both sides of a negative electrode current collector;
providing a first solid electrolyte layer; and
preparing a battery laminate by bringing the positive electrode active material layer of the positive electrode layer into contact with the negative electrode active material layer of the negative electrode layer through the first solid electrolyte layer;
When preparing the battery stack, an insulating layer is placed on the outer periphery of the first solid electrolyte layer, and the end faces of each layer of the battery stack are aligned at least at two locations on the outer periphery of the battery stack. Positioning in the stacking direction is performed by
A method for manufacturing an all-solid-state battery. The method for manufacturing an all-solid-state battery according to claim 7 or 8, wherein isotropic pressure is applied to said battery stack.

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