Electrode mixture slurry for solid-state battery, and method for producing electrode mixture slurry

Abstract

An electrode mixture slurry for a solid-state battery and a method for manufacturing the electrode mixture slurry are provided. The electrode mixture slurry contains an electrode active material, a solid electrolyte, and a dispersion medium, and the particle diameter of the electrode mixture slurry measured by a particle size meter method is 60 [mu] m or less. The method for producing an electrode mixture slurry includes: (i) preparing an electrode mixture slurry by applying a dispersion energy of 1.0 * 106 J / L or more to a preliminary electrode mixture slurry and stirring the preliminary electrode mixture slurry; and / or (ii) preparing an electrode mix slurry by stirring the preliminary electrode mix slurry until the particle diameter measured by the particle size meter method is 0.75 times or less with respect to the particle diameter measured by the particle size meter method when the preliminary electrode mix slurry is stirred while applying a dispersion energy of 5.0 * 105 J / L to the preliminary electrode mix slurry.

Description

Technical Field

[0001] The present disclosure relates to an electrode hybrid material slurry for a solid-state battery and a method for manufacturing the electrode hybrid material slurry. Background Art

[0002] In a solid-state battery, an electrode active material layer and a solid electrolyte layer are generally formed by coating an electrode hybrid material slurry and a solid electrolyte hybrid material slurry containing an electrode active material, a solid electrolyte, and a dispersion medium on the surface of a substrate, drying, and, if necessary, pressing. There is known a method for manufacturing an all-solid-state battery using the following binder composition and a solid electrolyte hybrid material slurry containing the above binder composition.

[0003] For example, Japanese Unexamined Patent Application Publication No. 2021-195374 discloses a binder composition containing a dispersion medium and a group of binder particles dispersed in the dispersion medium. The group of binder particles contains a polymer material, the polymer material contains a structural unit derived from vinylidene fluoride, the group of binder particles has a particle size distribution based on the number, and the particle size distribution satisfies the following formulas (1) to (3):

[0004] 0.19 ≤ X ≤ 0.26 (1)

[0005] 0.69 ≤ Y ≤ 0.76 (2)

[0006] 0 ≤ Z ≤ 0.05 (3)

[0007] Here, in the above formula (1), X represents the frequency of particles having a particle size of 40 μm or less. In the above formula (2), Y represents the frequency of particles having a particle size greater than 40 μm and 110 μm or less. In the above formula (3), Z represents the frequency of particles having a particle size greater than 110 μm and 250 μm or less. According to the binder composition of Japanese Unexamined Patent Application Publication No. 2021-195374, it is difficult to form aggregates in a slurry composition containing a sulfide solid electrolyte. Further, Japanese Unexamined Patent Application Publication No. 2021-195374 also discloses a method for manufacturing an all-solid-state battery, which includes: preparing a slurry composition by mixing the binder composition with a sulfide solid electrolyte; crushing the aggregates contained in the slurry composition; after crushing the aggregates, coating the slurry composition on the surface of a substrate and drying to form a separator; and manufacturing an all-solid-state battery including the separator. According to the method for manufacturing an all-solid-state battery of Japanese Unexamined Patent Application Publication No. 2021-195374, it is expected that by reducing aggregates, the deviation of the separator thickness becomes smaller and the discharge resistance of the all-solid-state battery is reduced. Summary of the Invention

[0008] In the method for manufacturing an all-solid-state battery disclosed in Japanese Patent Application Laid-Open No. 2021-195374, as described above, by reducing aggregates in the slurry for forming a solid electrolyte layer, the deviation in the thickness of the resulting separator (solid electrolyte layer) becomes smaller, and thus a reduction in the discharge resistance of the all-solid-state battery is expected.

[0009] In contrast, the inventors of the present application have found that, in the case of obtaining an electrode active material layer using an electrode mixture slurry, even when no aggregation is observed as a deviation in the thickness of the resulting electrode active material layer, the battery resistance increases due to minute aggregation.

[0010] Therefore, an object of the present disclosure is to provide an electrode mixture slurry for a solid-state battery and a method for manufacturing the electrode mixture slurry that can obtain an electrode active material layer with reduced battery resistance.

[0011] The present disclosure achieves the above object by the following means.

[0012] <Mode 1> An electrode mixture slurry, which is an electrode mixture slurry for a solid-state battery, wherein

[0013] the above electrode mixture slurry contains an electrode active material, a solid electrolyte, and a dispersion medium,

[0014] the particle size of the above electrode mixture slurry measured by a particle size meter method (particle gauge method) is 60 μm or less.

[0015] <Mode 2> The electrode mixture slurry according to Mode 1, wherein the above electrode mixture slurry contains a rubber-based binder.

[0016] <Mode 3> The electrode mixture slurry according to Mode 1 or 2, wherein the above electrode mixture slurry contains a negative electrode active material.

[0017] <Mode 4> A method for manufacturing an electrode mixture slurry, for manufacturing the electrode mixture slurry according to any one of Modes 1 to 3,

[0018] the method includes the following steps:

[0019] providing a preliminary electrode mixture slurry containing an electrode active material, a solid electrolyte, and a dispersion medium; and

[0020] (i) applying a dispersion energy of 1.0×10 6 J / L or more to the above preliminary electrode mixture slurry and stirring the above preliminary electrode mixture slurry to prepare the above electrode mixture slurry; and / or (ii) relative to applying 5.0×10 5The particle diameter measured by the particle size analyzer method when stirring the dispersion energy of J / L, and stirring the above-mentioned preliminary electrode mixture slurry until the particle diameter measured by the particle size analyzer method is 0.75 times or less, thereby preparing the above-mentioned electrode mixture slurry.

[0021] <Mode 5> An electrode active material layer, which is an electrode active material layer for a solid battery, wherein the maximum particle diameters of the electrode active material and the solid electrolyte measured by SEM image measurement (length measurement) of the cross-section of the electrode active material layer are 60 μm or less.

[0022] According to the electrode mixture slurry and the manufacturing method of the electrode mixture slurry of the present disclosure, an electrode active material layer capable of reducing battery resistance can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Hereinafter, the features, advantages, and technical and industrial significance of the exemplary embodiments of the present invention will be described with reference to the accompanying drawings, in which the same reference numerals denote the same elements, wherein:

[0024] Figure 1

[0025] Figure 1 It is a graph showing the relationship between the dispersion energy and the particle diameter of the negative electrode electrode mixture slurry in Examples 1 and 2 and Comparative Example 2. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Hereinafter, the embodiments of the present disclosure will be described in detail. It should be noted that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present disclosure.

[0027] Regarding the present disclosure, "mixture" refers to a composition that can form an electrode active material layer and a solid electrolyte layer as it is or by further containing other components. In addition, regarding the present disclosure, "mixture slurry" refers to a slurry that contains a dispersion medium in addition to the "mixture" and can be coated and dried to form an electrode active material layer and a solid electrolyte layer.

[0028] Regarding the present disclosure, a "solid battery" refers to a battery that uses at least a solid electrolyte as an electrolyte. Therefore, a solid battery can use a combination of a solid electrolyte and a liquid electrolyte as an electrolyte. In addition, a solid battery can be an all-solid battery, that is, a battery that uses only a solid electrolyte as an electrolyte.

[0029] "Electrode mixture slurry for solid battery"

[0030] In the electrode mixture slurry for a solid battery of the present disclosure,

[0031] ​​The electrode mixture material slurry contains an electrode active material, a solid electrolyte, and a dispersion medium.

[0032] The particle size of the electrode mixture material slurry measured by the granulometer method is 60 μm or less.

[0033] The electrode mixture material slurry according to the present disclosure can obtain an electrode active material layer that reduces the battery resistance.

[0034] The particle size obtained by the granulometer method is generally known as an index for obtaining a coating film with a uniform appearance in a slurry containing pigments and the like. The present inventors have found that the particle size of the electrode mixture material slurry measured by the granulometer method is related not only to the uniformity of the coating film but also to the battery resistance.

[0035] Specifically, for example, when the particle size of the electrode mixture material slurry measured by the granulometer method is 60 μm, an electrode active material layer with a uniform appearance can be obtained, and the resistance of the solid battery including the electrode active material layer formed from the electrode mixture material slurry is sufficiently low. On the other hand, even when the particle size of the electrode mixture material slurry measured by the granulometer method is 80 μm, an electrode active material layer with a uniform appearance can still be obtained. However, it is known that the resistance of the solid battery including the electrode active material layer formed from the electrode mixture material slurry becomes high. Although the electrode mixture material slurries have the same composition, due to the difference in the particle size obtained by the granulometer method, the performance shows a difference. Therefore, by making the particle size of the electrode mixture material slurry measured by the granulometer method 60 μm or less, not only can an electrode active material layer with a uniform appearance be obtained, but also an electrode active material layer that reduces the battery resistance can be obtained.

[0036] <Constitution of the Electrode Mixture Material Slurry for a Solid Battery>

[0037] The electrode mixture material slurry for a solid battery according to the present disclosure contains an electrode active material, a solid electrolyte, and a dispersion medium. Optionally, it may also contain a binder and a conductive additive. In addition to the above, the electrode mixture material slurry may also contain various additives.

[0038] The contents of the electrode active material, solid electrolyte, dispersion medium, etc. in the above-mentioned electrode mixture slurry can be appropriately determined according to the target slurry characteristics and battery performance. For example, when the total solid components of the electrode mixture slurry are set to 100 parts by mass, the content of the electrode active material can be 40 parts by mass or more, 50 parts by mass or more, or 60 parts by mass or more, and can also be 99 parts by mass or less or 90 parts by mass or less. Additionally, for example, the solid component concentration of the electrode mixture slurry (total solid components / (total solid components + dispersion medium)) can be 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, or 75% by mass or more, and can also be 90% by mass or less, 85% by mass or less, or 80% by mass or less.

[0039] (Electrode active material)

[0040] The electrode active material contained in the above-mentioned electrode mixture slurry can be a positive electrode active material or a negative electrode active material. There is no particular limitation on the electrode mixture slurry for the solid-state battery of the present disclosure, but it preferably contains a negative electrode active material.

[0041] (Negative electrode active material)

[0042] As the negative electrode active material, various materials with a potential for occluding and releasing lithium ions (charge-discharge potential) lower than that of the positive electrode active material can be used. There is no particular limitation on the material of the negative electrode active material, and it can be a material capable of occluding and releasing metal ions such as lithium ions. As the material capable of occluding and releasing metal ions such as lithium ions, for example, lithium titanate (Li 4 Ti 5 O 12 )), alloy-based negative electrode active materials, or carbon materials, etc., but not limited thereto.

[0043] As the alloy-based negative electrode active material, there is no particular limitation. For example, silicon alloy-based negative electrode active materials or tin alloy-based negative electrode active materials can be cited. Silicon alloy-based negative electrode active materials include silicon, silicon oxides, silicon carbides, silicon nitrides, or solid solutions thereof. Additionally, metal elements other than silicon can be included in the silicon alloy-based negative electrode active material, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. Tin alloy-based negative electrode active materials include tin, tin oxides, tin nitrides, or solid solutions thereof. Additionally, metal elements other than tin can be included in the Sn alloy-based negative electrode active material, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc.

[0044] As the carbon material, there is no particular limitation. For example, hard carbon, soft carbon, graphite, etc. can be cited.

[0045] The shape of the powder of the negative electrode active material is not particularly limited as long as it is a general shape of the negative electrode active material for a lithium ion battery. The negative electrode active material can be, for example, particulate. The negative electrode active material can be primary particles or secondary particles obtained by aggregating a plurality of primary particles. The average particle diameter D of the negative electrode active material as a raw material 50 can be, for example, 1 nm or more, 5 nm or more, or 10 nm or more, and can be 50 μm or less or 30 μm or less. It should be noted that the average particle diameter D 50 is the particle diameter (median particle diameter) at the cumulative value of 50% in the volume-based particle size distribution obtained by the laser diffraction / scattering method.

[0046] (Positive electrode active material)

[0047] The material of the positive electrode active material is not particularly limited. As the positive electrode active material, for example, lithium cobalt oxide (LiCoO 2 ), lithium nickel oxide (LiNiO 2 ), lithium manganate (LiMn 2 O 4 ), lithium nickel cobalt manganese oxide (NCM), LiCO 1 / 3 Ni 1 / 3 Mn 1 / 3 O 2 , lithium nickel cobalt aluminate (NCA; LiNi x Co y Al z O 2 ), a lithium-manganese spinel substituted with a foreign element represented by a composition of Li 1+x Mn 2-x-y M y O 4 (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn), etc., but is not limited thereto.

[0048] The positive electrode active material is not particularly limited and may have a coating layer. The coating layer is a layer containing a material having lithium ion conductivity, low reactivity with the positive electrode active material and the solid electrolyte, and capable of maintaining the form of a non-flowing coating layer even when in contact with the active material and the solid electrolyte. Specific examples of the material constituting the coating layer include, in addition to LiNbO 3 , Li 4 Ti 5 O 12 , Li 3 PO 4 , etc., but are not limited thereto.

[0049] The shape of the powder of the positive electrode active material is not particularly limited as long as it is a general shape of the positive electrode active material for a lithium ion battery. The positive electrode active material can be, for example, particulate. The positive electrode active material can be primary particles or secondary particles obtained by aggregating a plurality of primary particles. The average particle diameter D of the positive electrode active material as a raw material 50 can be, for example, 1 nm or more, 5 nm or more, or 10 nm or more, and can be 50 μm or less or 30 μm or less. It should be noted that the average particle diameter D 50 is the particle diameter (median diameter) at the cumulative value of 50% in the volume-based particle size distribution obtained by the laser diffraction / scattering method.

[0050] (Solid electrolyte)

[0051] The material of the solid electrolyte is not particularly limited, and can be, for example, a sulfide solid electrolyte, an oxide solid electrolyte, a polymer electrolyte, or the like.

[0052] Examples of the sulfide solid electrolyte include, but are not limited to, sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, or thiogermanate-type solid electrolytes. Examples of specific sulfide solid electrolytes include: Li 2 S-P 2 S 5 type (Li 7 P 3 S 11 , Li 3 PS 4 , Li 8 P 2 S 9 , etc.), Li 2 S-SiS 2 , LiI-Li 2 S-SiS 2 , LiI-Li 2 S-P 2 S 5 , LiI-LiBr-Li 2 S-P 2 S 5 , Li 2 S-P 2 S 5 -GeS 2 (Li 13 GeP 3 S 16 , Li 10 GeP 2 S 12 , etc.), LiI-Li 2 S-P 2 O 5, LiI - Li 3 PO 4 -P 2 S 5 , Li 7-x PS 6-x Cl x etc.; or combinations thereof, but not limited to this.

[0053] As examples of oxide solid electrolytes, the following can be cited: Li 7 La 3 Zr 2 O 12 , Li 7-x La 3 Zr 1-x Nb x O 12 , Li 7- 3x La 3 Zr 2 Al x O 12 , Li 3x La 2 / 3-x TiO 3 , Li 1+x Al x Ti 2-x (PO 4 ) 3 , Li 1+x Al x Ge 2-x (PO 4 ) 3 , Li 3 PO 4 , or Li 3+x PO 4- x N x (LiPON), etc., but not limited to this.

[0054] Sulfide solid electrolytes and oxide solid electrolytes can be glass or glass ceramics (crystalline glass).

[0055] As polymer electrolytes, polyethylene oxide (PEO), polypropylene oxide (PPO), and their copolymers, etc., can be cited, but not limited to this.

[0056] (Dispersion medium)

[0057] The dispersion medium is not particularly limited. Examples of the dispersion medium include decalin (1,2,3,4-tetrahydronaphthalene), anisole, xylene, octane, hexane, decahydronaphthalene, butyl acetate, ethyl propionate, tripropylamine, N-methyl-2-pyrrolidone (NMP), water, etc., but are not limited to these cases. The dispersion medium is not particularly limited and may be used alone as only one kind or two or more kinds may be used in combination.

[0058] (Binder)

[0059] As the binder, there is no particular limitation, and rubber-based binders, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyacrylic acid (PAA), etc. can be used. Examples of rubber-based binders include butadiene rubber (BR), styrene-butadiene rubber (SBR), etc., but are not limited thereto. The binder is not particularly limited and may be used alone as only one kind or two or more kinds may be used in combination. The electrode mixture material slurry for a solid battery of the present disclosure is not particularly limited and preferably contains a rubber-based binder.

[0060] (Conductive aid)

[0061] The conductive aid is not particularly limited. The conductive aid can be, for example, vapor-grown carbon fiber (VGCF), acetylene black (AB), Ketjen black (KB), carbon nanotube (CNT), carbon nanofiber (CNF), etc., but is not limited thereto. The conductive aid can be, for example, particulate or fibrous, and its size is not particularly limited. The conductive aid is not particularly limited and may be used alone as only one kind or two or more kinds may be used in combination.

[0062] (Particle size of the electrode mixture material slurry)

[0063] The particle size of the electrode mixture material slurry for a solid battery of the present disclosure measured by the particle size analyzer method is 60 μm or less.

[0064] The particle size of the above-mentioned electrode mixture material slurry measured by the particle size analyzer method can be evaluated according to JIS K5600-2-5 (1999). Specifically, the electrode mixture material slurry is dropped on the particle size analyzer stage, and is thinly stretched in the particle size analyzer groove using a spatula, and the point where a significant spot appears on the particle size analyzer is observed, and the particle size is obtained. Therefore, the particle size measured by the particle size analyzer method corresponds to the maximum particle size. The particle size of the electrode mixture material slurry measured by the particle size analyzer method can be 50 μm or less, 45 μm or less, or 40 μm or less, and can be 1 μm or more, 5 μm or more, 10 μm or more, 15 μm or more, 20 μm or more.

[0065] "Manufacturing method of the electrode mixture material slurry"

[0066] The electrode mixture material slurry for a solid battery of the present disclosure can be manufactured by the following steps:

[0067] Provide a preliminary electrode mixture material slurry containing an electrode active material, a solid electrolyte, and a dispersion medium; and

[0068] (i) Apply a dispersion energy of 1.0×10 6 J / L or more to the preliminary electrode mixture material slurry and stir the preliminary electrode mixture material slurry to prepare an electrode mixture material slurry; and / or (ii) Relative to the particle size measured by the particle size analyzer method when a dispersion energy of 5.0×10 5 J / L is applied to the preliminary electrode mixture material slurry and stirred, stir the preliminary electrode mixture material slurry until the particle size measured by the particle size analyzer method is 0.75 times or less to prepare an electrode mixture material slurry.

[0069] According to the method for manufacturing an electrode mixture material slurry for a solid battery of the present disclosure, an electrode mixture material slurry capable of forming an electrode active material layer that reduces the battery resistance can be obtained.

[0070] The present inventors have studied the dispersion energy during the preparation of the electrode mixture material slurry and found that when using an electrode mixture material slurry to which a dispersion energy of 1.0×10 6 J / L or more is applied to the preliminary electrode mixture material slurry, an electrode active material layer with reduced resistance can be obtained.

[0071] In addition, immediately after the dispersion energy is applied, the preliminary electrode mixture material slurry is uneven, so it is difficult to measure the particle size by the particle size analyzer method. On the other hand, when a dispersion energy of 5.0×10 5 J / L is applied to the preliminary electrode mixture material slurry and stirred, the unevenness of the preliminary electrode mixture material slurry can be eliminated, and the particle size can be easily measured by the particle size analyzer method. Moreover, it has been found that in the case of using an electrode mixture material slurry in which the particle size measured by the particle size analyzer method when a dispersion energy of 5.0×10 5 J / L is applied to the preliminary electrode mixture material slurry and stirred, and the dispersion energy is applied until the particle size is 0.75 times or less, an electrode active material layer with reduced resistance can also be obtained.

[0072] <Provision of the preliminary electrode mixture material slurry>

[0073] The preliminary electrode mixture material slurry of the present disclosure contains an electrode active material, a solid electrolyte, and a dispersion medium.

[0074] Regarding the electrode active material, solid electrolyte, and dispersion medium contained in the preliminary electrode mixture material slurry, reference can be made to the description in the above “<Composition of the electrode mixture material slurry for a solid battery>”. The preliminary electrode mixture material slurry is a precursor of the electrode mixture material slurry, and the particle size of the preliminary electrode mixture material slurry measured by the particle size analyzer method is not particularly limited.

[0075] As a preliminary electrode hybrid material slurry, a preliminary electrode hybrid material slurry prepared by mixing an electrode active material, a solid electrolyte, and a dispersion medium can be used, or a preliminary electrode hybrid material slurry mixed with an electrode active material, a solid electrolyte, and a dispersion medium can also be obtained and used.

[0076] <Dispersion energy application>

[0077] The method for manufacturing an electrode hybrid material slurry for a solid battery according to the present disclosure may include:

[0078] (i) Applying a dispersion energy of 1.0×10 6 J / L or more to the preliminary electrode hybrid material slurry and stirring the preliminary electrode hybrid material slurry to prepare an electrode hybrid material slurry; and / or

[0079] (ii) Stirring the preliminary electrode hybrid material slurry until the particle size measured by the particle size analyzer method is 0.75 times or less with respect to the particle size measured by the particle size analyzer method when a dispersion energy of 5.0×10 5 J / L is applied to the preliminary electrode hybrid material slurry and stirring is performed, thereby preparing an electrode hybrid material slurry.

[0080] (Dispersion energy)

[0081] The dispersion energy can be applied using, for example, an ultrasonic homogenizer (US600AT manufactured by Nippon Seiki Co., Ltd.), but is not limited to this case. The dispersion energy can be calculated from the output power and time when the dispersion energy is applied. In the case of using an ultrasonic homogenizer (US600AT manufactured by Nippon Seiki Co., Ltd.), the output power applied to the preliminary electrode hybrid material slurry is not particularly limited, and can be 150 W or more, 200 W or more, or 250 W or more, and can be 650 W or less, 600 W or less, or 550 W or less.

[0082] The dispersion energy applied to the preliminary electrode hybrid material slurry can be 1.5×10 6 J / L or more, 2.0×10 6 J / L or more, or 2.5×10 6 J / L or more, and can be 1.0×10 8 J / L or less, 1.0×10 7 J / L or less, 8.0×10 6 J / L or less, or 6.0×10 6 J / L or less.

[0083] The stirring method is not particularly limited, and a general method capable of stirring the electrode hybrid material slurry can be used.

[0084] <Others>

[0085] The electrode active material layer can be manufactured by a known method using the electrode mixture material slurry of the present disclosure. For example, the electrode mixture material slurry containing various components can be coated on a substrate and dried to form the electrode active material layer.

[0086] The method for forming a solid battery is not particularly limited, and a known method can be adopted. As a method for forming a solid battery, for example, a positive electrode current collector layer, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, a negative electrode current collector layer, a negative electrode active material layer, a solid electrolyte layer, a positive electrode active material layer, and a positive electrode current collector layer can be sequentially arranged and laminated and sealed to form a solid battery, but it is not limited to this case. The solid battery is not particularly limited, and for example, it can be constrained by an external pressure of 5 MPa.

[0087] It should be noted that by observing the SEM image of the cross-section of the electrode active material layer of the solid battery, it can be judged that the particle size measured by the particle size analyzer of the electrode mixture material slurry used in the formation of the solid battery is 60 μm or less. As described above, since the particle size measured by the particle size analyzer corresponds to the maximum particle size contained in the electrode mixture material slurry, if the maximum particle size observed in the SEM image is 60 μm or less, it can be judged that the particle size measured by the particle size analyzer is 60 μm or less.

[0088] The present disclosure will be described in more detail with reference to the following examples, but the scope of the present disclosure is not limited to these examples.

[0089] <<Example 1>>

[0090] <Preparation of negative electrode electrode mixture material slurry A1>

[0091] Li as the negative electrode active material 4 Ti 5 O 12 particles, Li as the solid electrolyte 2 S-P 2 S 5 class glass ceramics, styrene-butadiene rubber (SBR) class binder as the binder, conductive material carbon as the conductive aid, a dispersant and an appropriate amount of tetralin as the dispersion medium were mixed, and a dispersion energy of 1.0×10 6 J / L was applied using an ultrasonic homogenizer (US600AT manufactured by Nippon Seiki Co., Ltd.) and stirred, thereby obtaining the negative electrode electrode mixture material slurry A1. It should be noted that the dispersion energy is calculated from the output power and time of the ultrasonic homogenizer. The particle size of the negative electrode mixture material slurry A1 measured by the particle size analyzer is 60 μm.

[0092] <Fabrication of the negative electrode active material layer B1>

[0093] The negative electrode electrode mixture slurry A1 was coated on both sides of an aluminum foil serving as a negative electrode current collector by knife coating and dried, whereby the negative electrode active material layer B1 was fabricated on both sides of the aluminum foil. The negative electrode active material layer B1 has a uniform appearance without stripes or unevenness. It should be noted that the basis weight of the negative electrode active material layer was adjusted such that the charge specific capacity of the positive electrode active material contained in the positive electrode active material layer was 200 mAh / g, and the charge capacity of the negative electrode active material layer was 1 time that thereof.

[0094] <Fabrication of the solid electrolyte layer C1>

[0095] LiI-Li which is a solid electrolyte 2 S-P 2 S 5 type glass-ceramics, an SBR-based binder as an adhesive, carbon as a conductive additive, a dispersant and an appropriate amount of tetralin as a dispersion medium were mixed, and dispersion treatment was performed using an ultrasonic homogenizer (US600AT manufactured by Nippon Seiki Co., Ltd.), whereby a solid electrolyte mixture slurry was obtained. Next, the solid electrolyte mixture slurry was coated on the aluminum foil by knife coating and dried, whereby the solid electrolyte layer C1 was fabricated on the aluminum foil.

[0096] <Fabrication of the positive electrode active material layer D1>

[0097] LiNi coated with a Li-Ti-Al-F type material which is a positive electrode active material 0.8 (CoAl) 0.2 O 2 , Li which is a solid electrolyte 2 S-P 2 S 5 type glass-ceramics, an SBR-based binder as an adhesive, carbon as a conductive additive, a dispersant and an appropriate amount of tetralin as a dispersion medium were mixed, and dispersion treatment was performed using an ultrasonic homogenizer (US600AT manufactured by Nippon Seiki Co., Ltd.), whereby a positive electrode electrode mixture slurry was obtained. Next, the positive electrode mixture slurry was coated on the aluminum foil by knife coating and dried, whereby the positive electrode active material layer D1 was fabricated on the aluminum foil.

[0098] <Fabrication of the all-solid-state battery E1>

[0099] By laminating the solid electrolyte layer C1 on each surface of the negative electrode active material layer B1 formed on both sides of the aluminum foil and pressing, the solid electrolyte layer C1 is transferred onto the surface of the negative electrode active material layer B1. The aluminum foil in contact with the solid electrolyte layer C1 is peeled off, and the solid electrolyte layer C1 is laminated on the negative electrode active material layer B1. Next, by laminating the positive electrode active material layer D1 on each surface of the solid electrolyte layer C1 formed on both sides of the negative electrode active material layer B1 and pressing, the positive electrode active material layer D1 is transferred onto the surface of the solid electrolyte layer C1. The aluminum foil in contact with the positive electrode active material layer D1 is peeled off, and the positive electrode active material layer D1 is laminated on the solid electrolyte layer C1. By roll-pressing the fabricated laminate at 175 °C with 5 tons / cm, a densified laminate is obtained. Then, carbon-coated aluminum foil as the positive electrode current collector is disposed on each surface of the positive electrode active material layer of the densified laminate, and pressed at 140 °C with 5 MPa for 5 minutes, thereby obtaining a power generation element. Here, in the power generation element, carbon-coated aluminum foil, positive electrode active material layer D1, solid electrolyte layer C1, negative electrode active material layer B1, aluminum foil, negative electrode active material layer B1, solid electrolyte layer C1, positive electrode active material layer D1, and carbon-coated aluminum foil are laminated in sequence. The obtained power generation element is laminated and sealed, and constrained at 5 MPa, thereby obtaining an all-solid-state battery E1.

[0100] <Measurement of Resistance of All-Solid-State Battery E1>

[0101] The all-solid-state battery E1 is subjected to constant current charging at a current equivalent to 0.3C until it reaches a voltage equivalent to a 50% state of charge. Then, the all-solid-state battery E1 is discharged at a current value of 46C for 2 seconds. The potential difference between the voltage before discharge and the voltage after 2 seconds of discharge is obtained, and this potential difference is divided by the current value equivalent to 46C to calculate the battery resistance. The battery resistance of the all-solid-state battery C1 is 5.1 Ω.

[0102] <Example 2>

[0103] <Preparation of Negative Electrode Electrode Mixture Slurry A2>

[0104] Except that the dispersion energy is set to 2.5×10 6 J / L, the negative electrode electrode mixture slurry is prepared by the same method as in Example 1, thereby obtaining the negative electrode electrode mixture slurry A2. The particle size of the negative electrode electrode mixture slurry A2 measured by the particle size analyzer method is 40 μm.

[0105] <Fabrication of Negative Electrode Active Material Layer B2>

[0106] Except for using the negative electrode electrode mixture slurry A2, the negative electrode active material layer was fabricated by the same method as in Example 1, thereby obtaining the negative electrode active material layer B2. The negative electrode active material layer B2 had a uniform appearance without stripes or unevenness.

[0107] <Fabrication and Resistance Measurement of All-Solid-State Battery E2>

[0108] Except for using the negative electrode active material layer B1, the all-solid-state battery was fabricated by the same method as in Example 1, thereby obtaining the all-solid-state battery E2. The battery resistance of the all-solid-state battery E2 was calculated by the same method as that of the all-solid-state battery E1. The battery resistance of the all-solid-state battery E2 was 5.0 Ω.

[0109] <<Comparative Example 1>>

[0110] <Preparation of Negative Electrode Electrode Mixture Slurry a1>

[0111] Except for not applying the dispersion energy, i.e., setting the dispersion energy to 0 J / L, the negative electrode electrode mixture slurry was prepared by the same method as in Example 1, thereby obtaining the negative electrode electrode mixture slurry a1. The particle size of the negative electrode electrode mixture slurry a1 measured by the particle size analyzer method was 100 μm or more.

[0112] <Fabrication of Negative Electrode Active Material Layer b1>

[0113] Except for using the negative electrode electrode mixture slurry a1, the negative electrode active material layer was fabricated by the same method as in Example 1, thereby obtaining the negative electrode active material layer b1. The negative electrode active material layer b1 had a non-uniform appearance with stripes and unevenness.

[0114] <Fabrication of All-Solid-State Battery e1>

[0115] Due to many stripes and unevenness on the negative electrode active material layer b1, the all-solid-state battery e1 could not be fabricated.

[0116] <<Comparative Example 2>>

[0117] <Preparation of Negative Electrode Electrode Mixture Slurry a2>

[0118] Except for setting the dispersion energy to 5.0×10 5 J / L, the negative electrode electrode mixture slurry was prepared by the same method as in Example 1, thereby obtaining the negative electrode electrode mixture slurry a2. The particle size of the negative electrode electrode mixture slurry a2 measured by the particle size analyzer method was 80 μm.

[0119] <Fabrication of Negative Electrode Active Material Layer b2>

[0120] In addition to using the negative electrode electrode mixture paste a2, the negative electrode active material layer was fabricated by the same method as in Example 1, and thus the negative electrode active material layer b2 was obtained. The negative electrode active material layer b2 had a uniform appearance without stripes and unevenness.

[0121] <Fabrication and Resistance Measurement of All-Solid-State Battery e2>

[0122] In addition to using the negative electrode active material layer b2, the all-solid-state battery was fabricated by the same method as in Example 1, and thus the all-solid-state battery e2 was obtained. The battery resistance of the all-solid-state battery e2 was calculated by the same method as that of the all-solid-state battery C1. The battery resistance of the all-solid-state battery e2 was 5.6 Ω.

[0123] The results of Example 1, 2 and Comparative Example 1, 2 are shown in Table 1.

[0124]

[0125] As in the case of the negative electrode electrode mixture paste A1 of Example 1, when the particle diameter measured by the particle size analyzer method was 60 μm, an electrode active material layer with a uniform appearance could be obtained, and the battery resistance of the all-solid-state battery including the electrode active material layer formed from this electrode mixture paste was sufficiently low. On the other hand, as in the case of the negative electrode electrode mixture paste a2 of Comparative Example 2, when the particle diameter measured by the particle size analyzer method was 80 μm, an electrode active material layer with a uniform appearance could also be obtained. However, the battery resistance of the all-solid-state battery e2 including the electrode active material layer formed from this electrode mixture paste showed a high value of 5.6 Ω. It was clarified that by setting the particle diameter of the electrode mixture paste measured by the particle size analyzer method to 60 μm or less, not only a uniform electrode active material layer could be obtained, but also an electrode active material layer that reduced the battery resistance could be obtained.

[0126] In Figure 1 the relationship between the dispersion energy of Example 1, 2 and Comparative Example 2 and the particle diameter of the electrode mixture paste measured by the particle size analyzer method is shown. From Figure 1 it can be seen that when the dispersion energy increases, the particle diameter obtained by the particle size analyzer method becomes smaller. In particular, by applying a dispersion energy of 1.0×10 6 J / L or more, the particle diameter measured by the particle size analyzer method is 60 μm or less. Regarding the negative electrode electrode mixture paste A1 of Example 1 to which a dispersion energy of 1.0×10 6 J / L was applied, it was considered that the battery resistance of the all-solid-state battery E1 obtained from this negative electrode electrode mixture paste was sufficiently low. By applying a dispersion energy of 1.0×10 6 J / L or more, the particle diameter of the electrode mixture paste measured by the particle size analyzer method became sufficiently small, and thus an electrode active material layer that reduced the battery resistance could be obtained.

[0127] Although preferred embodiments of the electrode mixture material slurry for a solid-state battery and the method for manufacturing the electrode mixture material slurry according to the present disclosure are described, those skilled in the art understand that changes can be made without departing from the claims.

Claims

1. An electrode mixed material slurry is an electrode mixed material slurry for solid battery, wherein: The electrode mixed material slurry comprises an electrode active material, a solid electrolyte and a dispersion medium. The particle size of the electrode mixture slurry measured by a particle size analyzer method is 60 μm or less.

2. The electrode mixed material slurry according to claim 1, wherein: The electrode mixed material slurry contains a rubber-based binder.

3. The electrode mixed material slurry according to claim 1, wherein: The electrode mixed material slurry contains a negative electrode active material.

4. A method for producing an electrode mixed material slurry, comprising producing the electrode mixed material according to any one of claims 1 to 3, The manufacturing method comprises the following steps: providing a preliminary electrode mixed material slurry containing an electrode active material, a solid electrolyte and a dispersion medium; and (i) applying 1.0×10 6 J / L or more dispersion energy and stirring the prepared electrode mixed material slurry to prepare the electrode mixed material slurry; and / or (ii) With respect to applying 5.0×10 5 The electrode mixture slurry is prepared by stirring the preliminary electrode mixture slurry until the particle size measured by the particle size meter method is 0.75 times or less of the dispersion energy of J / L and stirring.

5. An electrode active material layer, which is an electrode active material layer for a solid battery, wherein The maximum particle size of the electrode active material and the solid electrolyte measured from a SEM image of a cross section of the electrode active material layer is 60 μm or less.

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