JP6772983B2 - Manufacturing method of all-solid-state battery - Google Patents

Description

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

In recent years, an all-solid-state battery in which an electrolytic solution is replaced with a solid electrolyte has attracted attention. Compared with a secondary battery that uses an electrolytic solution, an all-solid-state battery that does not use an electrolytic solution has high cycle durability and energy density without causing decomposition of the electrolytic solution due to overcharging of the battery. ing.

In such an all-solid-state battery, a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector layer are typically laminated. As an example of the manufacturing method of this all-solid-state battery, the following manufacturing method can be generally given.
(1) A slurry for an active material layer is applied on a current collector layer, and the slurry is dried or calcined to obtain an active material layer. Wet-on-dry manufacturing method to obtain a solid electrolyte layer by coating and drying or firing this;
(2) A slurry for a negative electrode active material layer is applied to form a slurry layer for a negative electrode active material layer, and a slurry for a solid electrolyte layer is applied thereto to form a slurry layer for a solid electrolyte layer. A wet-on-wet manufacturing method in which these are dried or fired to obtain a negative electrode active material layer and a solid electrolyte layer; and (3) a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material individually dried or fired. A manufacturing method of a laminated press method in which the laminated body is pressed after laminating the layers.

The all-solid-state battery obtained as described above has a positive electrode due to deformation due to processing such as cutting, deformation due to repeated charging and discharging, or partial damage due to vibration during use. The active material layer and the negative electrode active material layer may come into contact with each other and cause a short circuit. Therefore, the shape and structure of an all-solid-state battery capable of suppressing a short circuit, and a method for manufacturing the same are being studied.

In the method for producing a battery laminate of Patent Document 1, the first active material layer and the solid electrolyte layer are laminated, and the battery laminate is irradiated with a laser from the side of the first active material layer to irradiate the battery laminate with a solid electrolyte layer. The step of removing a part of the first active material layer is included, and the reflectance of the laser by the solid electrolyte layer is 80% or more. According to the method for manufacturing a battery laminate of Patent Document 1, the number of steps required for manufacturing a battery can be reduced, short circuits of batteries can be suppressed, and the performance thereof can be improved.

Japanese Unexamined Patent Publication No. 2016-21307

The present inventor irradiates a laser on the surface of the active material layer opposite to the laminated surface of the solid electrolyte layer in the manufacturing process of the all-solid-state battery in which the active material layer and the solid electrolyte layer are laminated. We found that the solid electrolyte layer could be thermally damaged.

Therefore, an object of the present invention is to provide a method for producing an all-solid-state battery capable of suppressing thermal damage of the solid electrolyte layer while removing a part of the active material layer.

The present inventors have found that the above problems can be solved by the following means.

<1> A method for manufacturing an all-solid-state battery in which an active material layer and a solid electrolyte layer are laminated so that the area of the active material layer is smaller than the area of the solid electrolyte layer.
By irradiating the surface of the active material layer on the side opposite to the laminated surface of the solid electrolyte layer with a laser, it is possible to remove a part of the active material layer while maintaining the solid electrolyte layer. Including
The active material layer contains the first solid electrolyte particles, and the solid electrolyte layer contains the second solid electrolyte particles.
The melting point of the second solid electrolyte particle is higher than the melting point of the first solid electrolyte particle.
Manufacturing method of all-solid-state battery.

According to the method of the present invention for producing an all-solid-state battery, it is possible to suppress thermal damage of the solid electrolyte layer while removing a part of the active material layer.

FIG. 1 is a diagram plotting the difference in melting point between Li ₃ PS ₄ and Li ₁₀ P ₂ GeS ₁₂ . FIG. 2 is a schematic view showing a state in which the laser is irradiated to the surface of the positive electrode active material layer opposite to the laminated surface of the solid electrolyte layer in the laminate of Example 1. FIG. 3 is a schematic view showing a state in which the laser is irradiated to the surface of the positive electrode active material layer opposite to the laminated surface of the solid electrolyte layer in the laminate of Example 2. FIG. 4 is a schematic view showing a state in which the laser is irradiated to the surface of the positive electrode active material layer opposite to the laminated surface of the solid electrolyte layer in the laminated body of the comparative example.

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be modified in various ways within the scope of the gist of the present invention. Further, in the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

<< Manufacturing method of all-solid-state battery >>
In the method of the present invention for producing an all-solid battery, the active material layer and the solid electrolyte layer are laminated so that the area of the active material layer is smaller than the area of the solid electrolyte layer, and the active material layer is solid. By irradiating the surface opposite to the laminated surface of the electrolyte layer with a laser, a part of the active material layer is removed while maintaining the solid electrolyte layer, where the active material layer is the first. The solid electrolyte layer contains one solid electrolyte particle, the solid electrolyte layer contains the second solid electrolyte particle, and the melting point of the second solid electrolyte particle is higher than the melting point of the first solid electrolyte particle.

As described above, the present inventor considered that one of the causes of thermal damage to the solid electrolyte layer is the properties of the active material layer and the laser output conditions. Specifically, this is not intended to be bound by any logic, but due to the non-uniformity of its thickness, density, etc. throughout the active material layer, it is processed with laser-processable parts. Difficult parts exist in the active material layer, and when these parts are treated with a laser of a predetermined output (particularly, an output capable of processing a difficult part), the active material layer is easily processed. This is believed to be due to the more excess laser light and / or energy such as heat propagating to the solid electrolyte layer.

In particular, when the compositions of the solid electrolyte particles contained in the active material layer and the solid electrolyte layer are the same, the energy for melting or removing the solid electrolyte particles in the active material layer is the same. Propagation to the solid electrolyte layer containing the solid electrolyte particles can cause thermal damage to the solid electrolyte layer.

From this, the present inventor paid attention to the melting point of the solid electrolyte particles contained in the active material layer and the solid electrolyte layer. Specifically, the present inventor has made the melting point of the second solid electrolyte particle contained in the solid electrolyte layer higher than the melting point of the first solid electrolyte particle contained in the active material layer. It was found that by selecting the first and second solid electrolyte particles, respectively, it is possible to suppress thermal damage of the solid electrolyte layer while removing a part of the active material layer, and completed the above-mentioned method of the present invention. I let you.

Further, in the method of the present invention for manufacturing an all-solid-state battery, the step of forming the active material layer and the solid electrolyte layer is not particularly limited, and any method can be adopted. As described above, examples of the steps for forming the active material layer and the solid electrolyte layer include a wet-on-dry manufacturing method, a wet-on-wet manufacturing method, and a laminated press manufacturing method. Can be done.

For example, in the wet-on-wet manufacturing method, the active material layer and the slurry layer for the solid electrolyte layer are laminated in this order by drying and firing the slurry layer for the active material layer and the slurry layer for the solid electrolyte layer. A solid electrolyte layer can be formed.

The temperature at which the slurry is dried and / or fired is not particularly limited, and examples thereof include temperatures in the range of room temperature to 500 ° C. The press pressure (for example, the press pressure in the laminated press method) is not particularly limited as long as a predetermined filling rate of each layer can be achieved. As the pressure of the press, for example, a pressure in the range of 50 MPa to 1000 MPa can be mentioned.

Hereinafter, the method of the present invention will be described in detail.

<All-solid-state battery>
In the all-solid-state battery, at least the active material layer and the solid electrolyte layer are laminated so that the area of the active material layer is smaller than the area of the solid electrolyte layer. In the present invention, the "active material layer" means a positive electrode active material layer or a negative electrode active material layer.

Typically, in an all-solid-state battery, the positive electrode current collector layer, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector layer are laminated in this order, or vice versa. It may be laminated.

Further, since these are laminated so that the area of the active material layer is smaller than the area of the solid electrolyte layer, for example, the positive electrode active material layer, the solid electrolyte layer, and the negative electrode containing the positive electrode active material are laminated. In an all-solid battery in which a negative electrode active material layer containing an active material is laminated, contact between the positive electrode active material and the negative electrode active material can be suppressed, and as a result, a short circuit of the all-solid battery can be suppressed.

(Active material layer)
The active material layer is a positive electrode active material layer or a negative electrode active material layer, and is formed on the solid electrolyte layer.

Examples of the thickness of the active material layer are not particularly limited, but may be 0.1 μm or more, 1 μm or more, 5 μm or more, or 10 μm or more, and / or 10000 μm or less, 1000 μm or less, or 500 μm or less, or 300 μm or less. Good.

(Active material layer: Positive electrode active material layer)
The positive electrode active material layer irradiated with the laser contains positive electrode active material particles, the first solid electrolyte particles, and optionally a conductive additive and a binder.

Examples of positive electrode active material particles include lithium metal oxide particles containing at least one transition metal selected from manganese, cobalt, nickel, and titanium and lithium, such as lithium cobaltate (Li _x CoO ₂ ) particles, nickel. Table lithium acid (LiNO ₂₎ particles, lithium manganate (LiMn ₂ O _{4) particles, Li 1 + x M y Mn} 2-x-y O 4 (M = Al, Mg, Fe, Cr, Co, Ni, Zn) Dissimilar element substitution spinel type lithium manganate, lithium titanate (Li _x TiO _y ), lithium metal phosphate (LiMPO ₄ : M = Fe, Mn, Co, Ni), and lithium nickel cobalt manganate (Li) _{1 + x} Ni _1/3 Co _1/3 Mn _1/3 O ₂ ) particles and the like, and combinations thereof can be mentioned.

Examples of the average particle size of the positive electrode active material particles are not particularly limited, but from the viewpoint of increasing the contact area of the solid interface, for example, an average particle size of 100 μm or less, 50 μm or less, 30 μm or less, or 20 μm or less can be mentioned. be able to. The average particle size may be 1 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, or 10 μm or more.

In the present invention, the "average particle size" is 10 or more, 100 or more, or 1000 or more randomly selected by means such as a scanning transmission electron microscope (STEM) unless otherwise specified. It refers to the arithmetic mean value of the measured values when the equivalent circle diameter (Heywood diameter) of the particles is measured.

Further, the positive electrode active material particles may optionally be coated with a buffer film. The buffer film preferably has an anion species that exhibits electron insulation and ionic conductivity and has a strong cation-binding force, and also contains positive electrode active material particles and solid electrolyte particles, particularly the first one. It is preferable that the morphology of the film that does not flow stably with respect to the solid electrolyte particles can be maintained. Examples of buffer membrane materials include LiNbO ₃ , Li ₄ Ti ₅ O ₁₂ , Li ₃ PO ₄ , and the like, and combinations thereof.

The thickness of the buffer membrane is not particularly limited, but may be, for example, 1 nm or more, 2 nm or more, or 3 nm or more, and / or 100 nm or less, 50 nm or less, or 20 nm or less.

The thickness of the buffer membrane is measured using, for example, a transmission electron microscope (TEM) or the like.

The example of the first solid electrolyte particles is not particularly limited as long as its melting point is lower than the melting point of the second solid electrolyte particles. Examples of the first solid electrolyte particles include sulfide-based amorphous solid electrolyte particles, for example, Li ₂ S-SiS ₂ , LiI-Li ₂ S-SiS ₂ , LiI-Li ₂ S-P ₂ S ₅ , _{LiI-Li 2 S-P 2} O 5, LiI-Li 3 PO 4 -P 2 S 5, and _Li 2 _S-P 2 _{S 5} or the like; sulfide-based crystalline solid electrolyte particles, for _example, Li _{7 P} 3 S ₁₁ , Li ₃ PS ₄ , Li _3.25 P _0.75 S _4, etc .; and combinations thereof can be mentioned.

The average particle size of the first solid electrolyte particles is not particularly limited, but may be, for example, 20 μm or less, 10 μm or less, 6 μm or less, or 3 μm or less from the viewpoint of increasing the contact area of the solid interface. The average particle size may be 0.1 μm or more, 0.2 μm or more, 0.3 μm or more, or 0.5 μm or more.

As the conductive auxiliary agent, carbon materials such as VGCF (gas phase growth method carbon fiber, Vapor Green Carbon Fiber), carbon black, acetylene black (AB), Ketjen black (KB), carbon nanotube (CNT), and carbon Examples thereof include nanofibers (CNFs) and the like, metal materials and the like, and combinations thereof.

The binder is not particularly limited, and examples thereof include polymer resins such as polyvinylidene fluoride (PVDF), butadiene rubber (BR), styrene butadiene rubber (SBR), and combinations thereof.

(Active material layer: Negative electrode active material layer)
The negative electrode active material layer irradiated with the laser contains negative electrode active material particles, the first solid electrolyte particles, and optionally a conductive additive and a binder.

The negative electrode active material particles are not particularly limited as long as they can occlude and release metal ions such as lithium ions. Examples of negative electrode active material particles include metal particles such as Li, Sn, Si, or In; lithium alloy particles, for example, lithium alloy particles of lithium and titanium, magnesium, aluminum, etc.; and carbon-based materials. For example, carbon, hard carbon, soft carbon, graphite and the like; and combinations thereof.

For the first solid electrolyte particles, the conductive additive, and the binder of the negative electrode active material layer, the description regarding the positive electrode active material layer can be referred to.

For example, in an all-solid battery in which a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer are laminated, the first solid electrolyte particle is an active material layer (for example, a positive electrode active material) irradiated with a laser. The solid electrolyte particles contained in the other active material layer (for example, the negative electrode active material layer) are not irradiated with the laser, and therefore, the solid electrolyte particles contained in the other active material layer may be contained. There is no particular limitation.

(Solid electrolyte layer)
The solid electrolyte layer is formed on the active material layer. The solid electrolyte layer contains a second solid electrolyte particle and an optional binder. For the binder of the solid electrolyte layer, the description regarding the positive electrode active material layer can be referred to.

The thickness of the solid electrolyte layer is not particularly limited, but may be 0.1 μm or more, 1 μm or more, 5 μm or more, or 10 μm or more, and / or 10000 μm or less, 1000 μm or less, or 500 μm or less, or 300 μm or less. Good.

The example of the second solid electrolyte particle is not particularly limited as long as its melting point is higher than the melting point of the first solid electrolyte particle. An example of the second solid electrolyte particle is a sulfide-based crystalline solid electrolyte particle, for example, a sulfide composed of LGPS (lithium, germanium, phosphorus, sulfur) such as Li ₁₀ P ₂ GeS ₁₂ (thio-LISIIO-based crystal). System crystalline) particles can be mentioned.

Examples of the first and second solid electrolyte particles are listed above. However, the first and second solid electrolyte particles are not limited to these examples as long as the melting point of the second solid electrolyte particles is higher than the melting point of the first solid electrolyte particles. Therefore, after satisfying the above melting point conditions, for example, the solid electrolyte particles listed as the first solid electrolyte particles may be used as the second solid electrolyte particles, and may be listed as the second solid electrolyte particles. The solid electrolyte particles obtained may be used as the first solid electrolyte particles.

(Current collector layer)
The current collector layer is laminated on the surface of the active material layer opposite to the surface of the active material layer on which the solid electrolyte layer is laminated. When the active material layer is a positive electrode active material layer, the current collector layer laminated therein is a positive electrode current collector layer, and when the active material layer is a negative electrode active material layer, the current collector layer is laminated therewith. The current collector layer to be formed is a negative electrode current collector layer.

The current collector layer is laminated on the active material layer after being irradiated with the laser. For another active material layer that is not treated by laser irradiation, the order in which the current collector layers are laminated with time is not particularly limited.

Examples of the positive electrode current collector layer or the negative electrode current collector layer are not particularly limited, and various metals such as silver, copper, gold, aluminum, nickel, iron, stainless steel, titanium, etc., and these are used. Alloys can be mentioned. From the viewpoint of chemical stability and the like, the positive electrode current collector layer is preferably an aluminum current collector layer, and the negative electrode current collector layer is preferably a copper current collector layer.

<laser>
The laser is applied to the surface of the active material layer opposite to the laminated surface of the active material layer and the solid electrolyte layer.

Examples of lasers are not particularly limited, but solid-state lasers such as Er: YAG lasers; gas lasers such as CO ₂ lasers; liquid lasers such as dye lasers; semiconductor lasers such as GaAlAs lasers; and Other known lasers can be mentioned.

<Others>
The components contained in the slurry for the active material layer and the slurry for the solid electrolyte layer, which are precursors of the active material layer and the solid electrolyte layer, respectively, are contained in the above-mentioned active material layer and the solid electrolyte layer, respectively. It may be substantially the same as the component. Further, for the purpose of obtaining the fluidity of the slurry, these slurries may optionally contain a dispersion medium.

Examples of dispersion media include non-polar solvents such as heptane, xylene, and toluene, and polar solvents such as tertiary amine solvents, ether solvents, thiol solvents, and ester solvents (eg butyl butyrate). Etc.) can be mentioned.

The present invention will be described in more detail with reference to the examples shown below, but the scope of the present invention is not limited to these examples.

<< Example 1 >>
<Preparation of positive electrode active material layer>
The positive electrode mixture as a raw material for the positive electrode active material layer was placed in a polypropylene (PP) container. This is stirred with an ultrasonic disperser (manufactured by SMT, model: UH-50) for 30 seconds, shaken with a shaker (manufactured by Shibata Scientific Technology, model: TTM-1) for 3 minutes, and described above. A slurry for the positive electrode active material layer was prepared by further stirring with an ultrasonic disperser for 30 seconds.

After shaking the slurry for the positive electrode active material for 3 minutes, the slurry for the positive electrode active material layer is coated on the Al foil as a release sheet by a blade method using an applicator, and the slurry layer for the positive electrode active material layer is applied. Was formed. This was dried on a hot plate at 100 ° C. for 30 minutes to obtain a positive electrode active material layer formed on the release sheet. By repeating the above operation, two positive electrode active material layers formed on the release sheet were prepared. The composition of the positive electrode mixture is shown below:
-LiNi _1/3 Co _1/3 Mn _1/3 O ₂ as positive electrode active material particles (average particle size 4 μm);
-Butyl butyrate as a dispersion medium;
-VGCF as a conductive aid;
Butyl butyrate solution (5% by mass) containing a PVdF-based binder as a binder;
-Li ₂ SP ₂ S ₅ series glass ceramics containing LiI as the first solid electrolyte particles (average particle size 0.8 μm, about 380 ° C.).

<Preparation of solid electrolyte layer>
The electrolyte mixture as a raw material for the solid electrolyte layer was placed in a polypropylene (PP) container. This is stirred with an ultrasonic disperser (manufactured by SMT, model: UH-50) for 30 seconds, and shaken with a shaker (manufactured by Shibata Kagaku Co., Ltd., model: TTM-1) for 30 minutes. A slurry for the solid electrolyte layer was prepared.

This solid electrolyte slurry was applied onto an Al foil as a release sheet by a blade method using an applicator. This was dried on a hot plate at 100 ° C. for 30 minutes to obtain a solid electrolyte layer formed on the release sheet. The above operation was repeated to prepare four solid electrolyte layers formed on the release sheet.

The composition of the electrolyte mixture is shown below:
-Li ₁₀ P ₂ GeS _12- based glass ceramics as the second solid electrolyte particles (average particle size 2.0 μm, about 690 ° C.);
-Butyl butyrate as a dispersion medium;
-Butyl butyrate solution containing a PVdF-based binder as a binder (5% by mass)

<Manufacturing of negative electrode laminate>
The negative electrode mixture as a raw material for the negative electrode active material layer was placed in a polypropylene (PP) container. This is stirred with an ultrasonic disperser (manufactured by SMT, model: UH-50) for 30 seconds, and shaken with a shaker (manufactured by Shibata Kagaku Co., Ltd., model: TTM-1) for 30 minutes. A slurry for the negative electrode active material layer was prepared.

By the blade method using an applicator, this slurry for the negative electrode active material layer was applied to both sides of the Cu foil as the current collector layer. This was dried on a hot plate at 100 ° C. for 30 minutes to obtain a negative electrode laminate in which negative electrode active material layers were formed on both sides of a Cu foil as a current collector layer.

The composition of the negative electrode mixture is shown below:
-Natural graphite-based carbon as negative electrode active material particles (manufactured by Mitsubishi Chemical Corporation, average particle size 10 μm);
-Butyl butyrate as a dispersion medium;
Butyl butyrate (5% by mass) containing a PVdF-based binder as a binder;
-Li ₂ SP ₂ S ₅ series glass ceramics containing LiI as a solid electrolyte (average particle size 1.5 μm).

<Manufacturing of laminated body>
The solid electrolyte layer formed on the release sheet was superposed on one of the negative electrode active material layers of the negative electrode laminate in which the negative electrode active material layers were formed on both sides of the Cu foil. Further, by performing the same operation on the other negative electrode active material layer of the negative electrode laminate, the solid electrolyte layer, the negative electrode active material layer, the current collector layer, the negative electrode active material layer, and the solid electrolyte layer are laminated in this order. The laminated body A to be obtained was obtained. After pressing the laminate A at a pressure of 400 MPa, the release sheets of the solid electrolyte layers on both sides of the laminate A were peeled off.

Further, the solid electrolyte layer formed on the release sheet was superposed on one of the solid electrolyte layers of the laminate A. Further, by performing the same operation on the other solid electrolyte layer of the laminate A, the two solid electrolyte layers, the negative electrode active material layer, the current collector layer, the negative electrode active material layer, and the two solid electrolyte layers are formed. A laminated body B laminated in this order was obtained. After pressing the laminate B at a pressure of 100 MPa, the release sheets existing on the solid electrolyte layers on both sides of the laminate B were peeled off.

Further, the positive electrode active material layer formed on the release sheet was superposed on one solid electrolyte layer of the laminate B. Further, by performing the same operation on the other solid electrolyte layer of the laminate B, the positive electrode active material layer, the two solid electrolyte layers, the negative electrode active material layer, the current collector layer, the negative electrode active material layer, and the two A laminated body C in which the solid electrolyte layer and the positive electrode active material layer were laminated in this order was obtained. After pressing the laminate C at a pressure of 400 MPa, the release sheets existing on the positive electrode active material layers on both sides of the laminate C were peeled off. As a result, the laminate of Example 1 was produced.

<< Example 2 >>
Examples were the same as in Example 1 except that the solid electrolyte particles of the negative electrode mixture of Example 1 were replaced with the second solid electrolyte particles (Li ₁₀ P ₂ GeS _12- based glass ceramics) of the solid electrolyte layer. A laminate of 2 was produced.

<< Comparative example >>
The same as in Example 1 except that the solid electrolyte particles contained in the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer of Example 1 were all replaced with Li ₃ PS ₄ glass ceramics. A laminated body of Comparative Example was prepared.

The difference in melting point between Li ₃ PS ₄ used in the comparative example and Li ₁₀ P ₂ GeS ₁₂ used in the solid electrolyte layer of Example 1 and the solid electrolyte layer and the negative electrode active material layer of Example 2 is shown in FIG. It is shown in 1. As can be seen from FIG. 1, the melting point of Li ₃ PS ₄ is about 380 ° C., and the melting point of Li ₁₀ P ₂ GeS ₁₂ is about 690 ° C.

《Evaluation》
The laminates of Examples 1 and 2 and Comparative Example were irradiated with a laser, and the degree of thermal damage of the solid electrolyte layer was evaluated. Details of the laser are shown below:
Wavelength: 1030 nm
Oscillation type: Pulse oscillation Fluence: 3000J / cm ²

FIGS. 2 to 4 show that in the laminated bodies of Examples 1 and 2, respectively, the surface of the positive electrode active material layer opposite to the laminated surface of the solid electrolyte layer is irradiated with the laser. It is a schematic diagram which shows. In these figures, only the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer of the laminates of Examples 1 and 2 and Comparative Examples are shown, and other configurations are not shown.

As described above, in the laminated body of the comparative example in which Li ₃ PS ₄ was adopted as the first solid electrolyte particles of the positive electrode active material layer and the second solid electrolyte particles of the solid electrolyte layer, the solid electrolyte layer was heated. Damaged. FIG. 4 shows that the thermal energy of the laser 200 propagates to the solid electrolyte layer 120, and the solid electrolyte layer 120 is thermally damaged.

This is because there are parts that are easily processed by the laser and parts that are difficult to process in the active material layer due to the non-uniformity of the thickness and density of the entire positive electrode active material layer, and these parts have a predetermined output ( In particular, when processed with a laser (output that can process difficult-to-process parts), more excess laser light and / or energy such as heat is generated in the easily processed part of the positive electrode active material layer of the solid electrolyte. It is considered that the solid electrolyte layer propagating to the layer and thereby containing Li ₃ PS ₄ as the solid electrolyte particles was thermally damaged as in the positive electrode active material layer.

On the other hand, as described above, an example in which Li ₃ PS ₄ was adopted as the first solid electrolyte particle in the positive electrode active material layer and Li ₁₀ P ₂ GeS ₁₂ was adopted as the second solid electrolyte particle in the solid electrolyte layer. In the laminate of Example 1 and the laminate of Example 2, the solid electrolyte layer was not thermally damaged. FIGS. 2 and 3 show that the solid electrolyte layer 120 is substantially undamaged even when the thermal energy of the laser 200 propagates to the solid electrolyte layer 120.

This is because the melting point (about 690 ° C.) of the second solid electrolyte particles (Li ₁₀ P ₂ GeS ₁₂ ) contained in the solid electrolyte layer is contained in the active material layer, and the first solid electrolyte particles (Li) are contained. ₃ PS ₄ ) is higher than the melting point (about 380 ° C.), so the heat of the solid electrolyte layer containing the second solid electrolyte particles is removed while removing a part of the positive electrode active material layer containing the first solid electrolyte particles. It is probable that the damage could be suppressed.

Although the preferred embodiment of the method of the present invention has been described in detail, the device or chemical, the manufacturer and grade thereof, the position and arrangement of the production line, etc., which are adopted in the method of the present invention without departing from the scope of claims. Those skilled in the art understand that changes can be made to.

110 Positive electrode active material layer 120 Solid electrolyte layer 130 Negative electrode active material layer 200 Laser

Claims (1)

A method for manufacturing an all-solid-state battery in which an active material layer and a solid electrolyte layer are laminated so that the area of the active material layer is smaller than the area of the solid electrolyte layer.
By irradiating the surface of the active material layer on the side opposite to the laminated surface of the solid electrolyte layer with a laser, a part of the active material layer can be removed while maintaining the solid electrolyte layer. Including
The active material layer contains the first solid electrolyte particles, and the solid electrolyte layer contains the second solid electrolyte particles.
The melting point of the second solid electrolyte particle is higher than the melting point of the first solid electrolyte particle.
Manufacturing method of all-solid-state battery.

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