JP2022156195A - Manufacturing method for all-solid-state battery - Google Patents

Abstract

To provide a manufacturing method for an all-solid-state battery with improved productivity.SOLUTION: The manufacturing method for an all-solid-state battery includes the steps of preparing a laminated body in which a plurality of solid electrolyte structures 40 having a foil which is a magnetic material and a layer including a solid electrolyte laminated on the foil are laminated, arranging the laminated body in a container 60, applying a magnetic force to the laminated body to form a gap between adjacent solid electrolyte structures, and inserting a layer including a positive electrode active material or a layer including a negative electrode active material into the gap.SELECTED DRAWING: Figure 10

Description

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

An all-solid-state battery includes a positive electrode including a positive electrode active material layer, a negative electrode including a negative electrode active material layer, and a solid electrolyte layer including a solid electrolyte disposed therebetween. It needs to be layered well.

Patent Literature 1 discloses a work stacking method for stacking components to be stacked one by one using a pick-and-place device.

JP-A-7-97063

The conventional technique described above has a problem in that it takes a long time to stack the layers one by one.
Therefore, an object of the present disclosure is to provide a method for manufacturing an all-solid-state battery that can improve productivity.

As one means for solving the above problems, the present disclosure provides a method for manufacturing an all-solid-state battery, which comprises a solid electrolyte structure having a foil that is a magnetic material and a layer containing a solid electrolyte laminated on the foil. a step of preparing a laminate in which a plurality of layers are laminated; a step of placing the laminate in a container; a step of applying a magnetic force to the laminate to form a gap between adjacent solid electrolyte structures; and a positive electrode active material in the gap. or a step of inserting a layer containing a negative electrode active material.

Advantageous Effects of Invention According to the present disclosure, many laminates can be produced at once, the time required for the lamination process can be shortened, and the productivity of all-solid-state batteries can be improved.

FIG. 1 is a diagram for explaining the layer structure of an all-solid-state battery 10. FIG. FIG. 2 is a diagram for explaining the layer structure of the positive electrode structure 20. As shown in FIG. FIG. 3 is a diagram for explaining the layer structure of the negative electrode structure 30. As shown in FIG. FIG. 4 is a diagram for explaining the layer structure of the solid electrolyte structure 40. As shown in FIG. FIG. 5 is a diagram illustrating lamination of the positive electrode structure 20 and the solid electrolyte structure 40. As shown in FIG. FIG. 6 is a diagram showing a laminate of a plurality of solid electrolyte structures 40. As shown in FIG. 7A and 7B are diagrams for explaining a scene in which a stack of a plurality of solid electrolyte structures 40 is arranged in a container 60. FIG. FIG. 8 is a diagram illustrating a scene in which a stack of multiple solid electrolyte structures 40 is arranged in a container 60. As shown in FIG. FIG. 9 is a diagram illustrating a situation in which a plurality of solid electrolyte structures 40 are arranged with gaps therebetween by the action of magnetic force. 10A and 10B are diagrams for explaining a scene in which the positive electrode structure 20 is arranged in the gaps between the plurality of solid electrolyte structures 40. FIG. FIG. 11 is a diagram for explaining a scene in which the solid electrolyte structures 40 and the positive electrode structures 20 are alternately arranged. FIG. 12 is a diagram showing a laminate in which solid electrolyte structures 40 and positive electrode structures 20 are alternately arranged.

1. All-solid-state battery The configuration of a typical all-solid-state battery will be described. FIG. 1 shows a schematic cross-sectional view showing an example of an all-solid-state battery. As shown in FIG. 1, an all-solid-state battery 10 includes a positive electrode active material layer 11 containing a positive electrode active material, a negative electrode active material layer 12 containing a negative electrode active material, and a layer between the positive electrode active material layer 11 and the negative electrode active material layer 12. It has a solid electrolyte layer 13 formed therebetween, a positive electrode current collector layer 14 that collects current from the positive electrode active material layer 11 , and a negative electrode current collector layer 15 that collects current from the negative electrode active material layer 12 .
Each configuration of the all-solid-state battery 10 will be described below.

1.1. Positive Electrode Active Material Layer The positive electrode active material layer 11 is a layer containing a positive electrode active material, and if necessary, may further contain at least one of a solid electrolyte material, a conductive material, and a binder.
A known active material may be used as the positive electrode active material. For example, cobalt _- based (LiCoO2, etc.), nickel _- based ( _LiNiO2 , etc.), manganese _- based ₍ LiMn2O4, _{Li2Mn2O3 ,} etc.), iron phosphate _- based _{( LiFePO4} , _Li2FeP2O7 , etc.) ), NCA series (nickel, cobalt and aluminum compounds), NMC series (nickel, manganese and cobalt compounds) and the like. More specifically, there are LiNi _1/3 Co _1/3 Mn _1/3 O ₂ and the like.
The surface of the positive electrode active material may be coated with an oxide layer such as a lithium niobate layer, a lithium titanate layer, or a lithium phosphate layer.

The solid electrolyte is preferably an inorganic solid electrolyte. This is because they have higher ionic conductivity and superior heat resistance than organic polymer electrolytes. Examples of inorganic solid electrolytes include sulfide solid electrolytes and oxide solid electrolytes.
Examples of sulfide solid electrolyte materials having Li ion conductivity include Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -LiI, Li ₂ SP ₂ S ₅ -Li ₂ O, Li _{2SP2S5 -} Li2O _- LiI, _{Li2S - SiS2} , _{Li2S -} SiS2 _- LiI, Li2S _- SiS2 _- LiBr, Li2S _- SiS2 _- LiCl, Li2 S—SiS ₂ —B ₂ S ₃ —LiI, Li ₂ S—SiS ₂ —P ₂ S ₅ —LiI, Li ₂ S—B ₂ S ₃ , Li ₂ SP ₂ S ₅ —ZmSn (where m, n is a positive number, and Z is one of Ge, Zn, and Ga.), Li ₂ S—GeS ₂ , Li ₂ S—SiS ₂ —Li ₃ PO ₄ , Li ₂ S—SiS ₂ —LixMOy (where x and y are positive numbers, and M is one of P, Si, Ge, B, Al, Ga, and In.). The above description of "Li ₂ SP _{2 S 5 " means a sulfide solid electrolyte material using a raw material composition containing Li 2 S and P 2 S 5 , and} the same applies to other descriptions. be.

On the other hand, examples of oxide solid electrolyte materials having Li ion conductivity include compounds having a NASICON structure. Examples of compounds having a NASICON structure include compounds represented by the general formula Li _1+x Al _x Ge _2-x (PO ₄ ) ₃ (0≦x≦2) (LAGP) and general formula Li _1+x Al _x Ti _{2 -x} (PO ₄ ) ₃ (0≦x≦2) (LATP) and the like. Other examples of oxide solid electrolyte materials include LiLaTiO (eg, Li _0.34 La _0.51 TiO ₃ ), LiPON (eg, Li _2.9 PO _3.3 N _0.46 ), LiLaZrO ( For _{example , Li7La3Zr2O12} ) etc. can be _mentioned .

The binder is not particularly limited as long as it is chemically and electrically stable. Examples include rubber-based binders such as butadiene rubber (SBR), olefin-based binders such as polypropylene (PP) and polyethylene (PE), and cellulose-based binders such as carboxymethylcellulose (CMC).
As the conductive material, carbon materials such as acetylene black (AB), ketjen black, and carbon fiber, and metal materials such as nickel, aluminum, and stainless steel can be used.

The content of each component in the positive electrode active material layer 11 and the shape of the positive electrode active material layer 11 may be the same as conventional ones. In particular, the sheet-like positive electrode active material layer 11 is preferable from the viewpoint that the all-solid-state battery 10 can be easily constructed. In this case, the thickness of the positive electrode active material layer 11 is, for example, preferably 0.1 μm or more and 1 mm or less, and more preferably 1 μm or more and 150 μm or less.

1.2. Negative Electrode Active Material Layer The negative electrode active material layer 12 is a layer containing at least a negative electrode active material. A binding material, a conductive material, and a solid electrolyte material may be included as necessary. The binding material, the conductive material, and the solid electrolyte material can be considered in the same manner as the positive electrode active material layer 11 .

The negative electrode active material is not particularly limited, but when forming a lithium ion battery, the negative electrode active material may be carbon materials such as graphite or hard carbon, various oxides such as lithium titanate, Si or Si alloys, Alternatively, metallic lithium, lithium alloys, and the like can be mentioned.

The content and shape of each component in the negative electrode active material layer 12 may be the same as conventional ones. In particular, the sheet-like negative electrode active material layer 12 is preferable from the viewpoint that the all-solid-state battery 10 can be easily constructed. In this case, the thickness of the negative electrode active material layer 12 is, for example, preferably 0.1 μm or more and 1 mm or less, and more preferably 1 μm or more and 150 μm or less.

1.3. Solid Electrolyte Layer The solid electrolyte layer 13 is a layer containing a solid electrolyte disposed between the positive electrode active material layer 11 and the negative electrode active material layer 12 . Solid electrolyte layer 13 contains at least a solid electrolyte material. The solid electrolyte material can be considered in the same manner as the solid electrolyte material described for the positive electrode active material layer 11 .

1.4. Current Collector Layer The current collectors are a positive electrode current collector layer 14 that collects current for the positive electrode active material layer 11 and a negative electrode current collector layer 15 that collects current for the negative electrode active material layer 12 . Examples of materials that constitute the positive electrode current collector layer 14 include stainless steel, aluminum, nickel, iron, titanium, and carbon. On the other hand, examples of materials forming the negative electrode current collector layer 15 include stainless steel, copper, nickel, and carbon.

1.5. Battery Case The all-solid-state battery may include a battery case (not shown). A battery case is a case for housing each member, and examples thereof include a battery case made of stainless steel.

2. Manufacturing method of all-solid-state battery 2.1. Overview of Manufacturing All-Solid-State Battery First, an overview of the method for manufacturing an all-solid-state battery will be described.

[Fabrication of positive electrode structure]
Materials constituting the positive electrode active material layer are kneaded to obtain a slurry positive electrode composition. After that, the prepared slurry positive electrode composition is applied to the surface of the material that will be the positive electrode current collector layer, and the layer that will be the positive electrode active material layer is formed through the process of heating and drying, and pressurized. A positive electrode structure 20 having a layer 21 serving as a positive electrode current collector layer and a layer 22 serving as a positive electrode active material layer is obtained as shown in FIG.

[Preparation of negative electrode structure]
Materials constituting the negative electrode active material layer are kneaded to obtain a slurry negative electrode composition. After that, the prepared slurry negative electrode composition is applied to the surface of the material that will become the negative electrode current collector layer, and the layer that will become the negative electrode active material layer is formed through the process of heating and drying, followed by pressing. A negative electrode structure 30 having a layer 31 to be a negative electrode current collector layer and a layer 32 to be a negative electrode active material layer is obtained as shown in FIG.

[Preparation of Solid Electrolyte Layer Structure]
Materials constituting the solid electrolyte layer are kneaded to obtain a slurry-like solid electrolyte layer composition. After that, the prepared slurry-like solid electrolyte layer composition is applied to the surface of a foil of a magnetic material such as iron or nickel, and a layer that becomes a solid electrolyte layer is formed through a process of heating and drying. As described above, the solid electrolyte layer structure 40 having the magnetic foil 41 and the layer 42 to be the solid electrolyte layer is obtained.

[Combination of each structure]
As shown in the upper diagram of FIG. 5, the layer 42 that will be the solid electrolyte layer of the solid electrolyte layer structure 40 and the layer 22 that will be the positive electrode active material layer of the positive electrode structure 20 are stacked (the positive electrode structure and the solid layer). stacking step with the electrolyte structure), the magnetic foil 41 of the solid electrolyte structure 40 is removed as shown in the lower part of FIG.
Further, the layer 32 to be the negative electrode active material layer of the negative electrode structure 30 is laminated on the transferred layer 42 to be the solid electrolyte to obtain an all-solid battery.

2.2. Lamination step of positive electrode structure and solid electrolyte structure In the manufacturing method of the solid battery of the present disclosure, among the above-described steps, in the step of stacking the positive electrode structure and the solid electrolyte structure, a large amount of the lamination is efficiently performed. Disclose what you do. 6 to 12 show diagrams for explanation.

[Laminate of Solid Electrolyte Structure]
First, as shown in FIG. 6, a laminate in which a plurality of solid electrolyte structures 40 are laminated is prepared. The lamination is arranged so that the sheet surfaces of the sheet-shaped solid electrolyte structures 40 overlap each other, and the magnetic foils 41 and the layers 42 that become the solid electrolyte layers are alternately laminated.

[Arrangement of laminate]
As shown in FIGS. 7 and 8, the prepared stack of solid electrolyte structures is placed inside the groove 60a of the container 60 in which the groove 60a is formed. In this arrangement, as can be seen from FIG. 7, the plurality of solid electrolyte structures 40 are arranged in the grooves 60a so that the stacking direction is horizontal.
Here, a magnet 61 is arranged at a position adjacent to the container 60 so as to extend along the direction in which the groove 60a of the container 60 extends. The position of the magnet 61 with respect to the container 60 is not particularly limited, and may be provided on the bottom side of the groove 60a as in this embodiment, or may be provided on the side.
As shown by arrow A in FIG. 7, the prepared laminate of solid electrolyte structures is sandwiched from the stacking direction and held, and arranged inside groove 60a as shown by arrow B. make it A method for holding the stack of solid electrolyte structures is not particularly limited, and any device that can move the stack while physically sandwiching the stack may be used.

[Unloading]
The force sandwiching the stack of solid electrolyte structures is released. As a result, as shown in FIG. 9, the individual solid electrolyte structures 40 move apart from each other with a gap. This is because the magnetic foil 41 provided in the solid electrolyte structure 40 becomes magnetized by the action of the magnetic force received from the magnet 61 and temporarily becomes a magnet, and the magnetic foil 41 of the adjacent solid electrolyte structure 40 repels it. Due to the action of force. In addition, in FIG. 9, the gap between the adjacent solid electrolyte structures 40 is exaggeratedly shown for ease of understanding.

[Insertion of positive electrode structure]
9, the positive electrode structure 20 is inserted into the gap, as shown in FIG.
Although the insertion method is not particularly limited, for example, the positive electrode structure 20 can be moved from a plurality of guide rails and inserted into each of the plurality of gaps at the same time.
Thereby, as shown in FIG. 11, the solid electrolyte structures 40 and the positive electrode structures 20 are alternately arranged.

[take out]
With the solid electrolyte structures 40 and the positive electrode structures 20 alternately arranged as shown in FIG. The positive electrode structures 20 are moved to obtain a laminate in which the solid electrolyte structures 40 and the positive electrode structures 20 are alternately arranged as shown in FIG. That is, this laminate is obtained by laminating a plurality of laminates having the layer structure shown in the upper diagram of FIG.

[Effects, etc.]
In this way, by having the stacking process of the positive electrode structure and the solid electrolyte structure of the present disclosure, many stacks can be produced at once, the time of the stacking process can be shortened, and the all-solid-state battery can be manufactured. Productivity can be improved.

2.3. Others Although the positive electrode structure 20 is first laminated on the solid electrolyte structure 40 in the above description, the negative electrode structure 30 may be laminated first instead. Even in this case, the order of the positive electrode structure 20 and the negative electrode structure 30 is merely changed, and an all-solid-state battery can be manufactured in the same manner as described above.

In the above description, an example in which a magnetic force is constantly generated and the solid electrolyte structure 40 is moved by the action of the magnetic force due to unloading has been described. After being loaded, the magnetic force may be supplied and acted upon.

10 All-solid battery 11 Positive electrode active material layer 12 Negative electrode active material layer 13 Solid electrolyte layer 14 Positive electrode current collector layer 15 Negative electrode current collector layer 20 Positive electrode structure 30 Negative electrode structure 40 Solid electrolyte structure

Claims (1)

A method for manufacturing an all-solid-state battery,
A step of preparing a laminate obtained by laminating a plurality of solid electrolyte structures having a magnetic foil and a layer containing a solid electrolyte laminated on the foil;
placing the laminate in a container;
applying a magnetic force to the laminate to form a gap between the adjacent solid electrolyte structures;
inserting a layer containing a positive electrode active material or a layer containing a negative electrode active material into the gap;
A method for manufacturing an all-solid-state battery.

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