Method for producing electrode composite powder

Abstract

According to the method of the present disclosure, the load on the apparatus can be suppressed when the active material particles and the sulfide solid electrolyte are kneaded.SOLUTION: The method of the present disclosure for producing an electrode composite powder includes (a) kneading active material particles and a sulfide solid electrolyte while adding a solvent, and (b) after the step (a), kneading the active material particles and the sulfide solid electrolyte without adding the solvent to deform the sulfide solid electrolyte at least partially. And coating at least a part of a surface of the active material particle with the sulfide solid electrolyte, wherein a kneading speed in the step (a) is smaller than a kneading speed in the step (b), and the electrode composite powder has the active material particle and the sulfide solid electrolyte.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a method for producing an electrode composite powder. [Background technology]

[0002] Sulfide solid electrolytes have both high ionic conductivity and relatively good deformability. Sulfide solid electrolytes are suitable for bulk-type all-solid-state batteries. However, direct contact of the sulfide solid electrolyte with the active material in the electrode active material layer can accelerate degradation of the sulfide solid electrolyte. Degradation of the sulfide solid electrolyte can result in, for example, a loss of ionic conductivity.

[0003] To reduce direct contact between the sulfide solid electrolyte and the active material, it has been proposed to form composite particles by coating the active material with an oxide solid electrolyte (e.g., LiNbO3).Furthermore, it has also been proposed to coat the composite particles with the sulfide solid electrolyte to promote interface formation between the composite particles and the sulfide solid electrolyte.

[0004] For example, Patent Document 1 discloses a composite active material characterized by comprising active material particles containing at least one of cobalt, nickel, and manganese and further containing lithium and oxygen, composite particles containing an oxide-based solid electrolyte covering all or part of the surfaces of the active material particles, and a sulfide-based solid electrolyte further covering 76.0% or more of the surfaces of the composite particles. The composite active material described in Patent Document 1 is said to be able to reduce the reaction resistance of lithium batteries.

[0005] Furthermore, Patent Document 2 discloses an all-solid-state battery comprising: a solid electrolyte layer containing an oxide-based solid electrolyte as a main component; a first electrode layer formed on a first main surface of the solid electrolyte layer and containing a positive electrode active material and a Li-La-Ti-O-based oxide; and a second electrode layer formed on a second main surface of the solid electrolyte layer and containing a positive electrode active material and a Li-La-Ti-O-based oxide. The all-solid-state battery described in Patent Document 2 is said to be easy to fabricate and to allow the operating voltage to be freely designed.

[0006] Furthermore, Patent Document 3 discloses an electrode material having a solid content of 72% or more, comprising composite particles, a sulfide solid electrolyte, and a solvent, the composite particles comprising an active material and a fluoride solid electrolyte, the fluoride solid electrolyte covering at least a portion of the surface of the active material, and the sulfide solid electrolyte adhering to the composite particles. The electrode material described in Patent Document 3 is said to be able to reduce the rate of increase in resistance after endurance testing. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-154407 [Patent Document 2] Japanese Patent Publication No. 2020-053307 [Patent Document 3] Japanese Patent Application Publication No. 2024-008476 Summary of the Invention [Problem to be solved by the invention]

[0008] One method for coating active material particles with a sulfide solid electrolyte is a wet process. In the wet process, a solvent is added and the active material particles and sulfide solid electrolyte are kneaded together to deform at least a portion of the sulfide solid electrolyte, which then coats the active material particles. In the wet process, adding a solvent to change the solid content (NV: Nonvolatile Content) of the kneaded mixture changes the shear stress of the mixture. In this regard, there is a concern that the solid content of the kneaded mixture is nonuniform immediately after adding the solvent, which may result in locally high mechanical loads on the device.

[0009] Therefore, an object of the present disclosure is to reduce the mechanical load on the kneading device. [Means for solving the problem]

[0010] The present disclosure achieves the above object by the following means.

[0011] (Aspect 1) A method for producing an electrode composite powder, comprising: (a) kneading the active material particles and the sulfide solid electrolyte while adding a solvent; and (b) after step (a), kneading the active material particles and the sulfide solid electrolyte without adding a solvent to at least partially deform the sulfide solid electrolyte and coat at least a portion of the surface of the active material particles with the sulfide solid electrolyte; and The kneading speed in step (a) is lower than the kneading speed in step (b), and The electrode composite powder includes the active material particles and the sulfide solid electrolyte. Manufacturing method of electrode composite powder. (Aspect 2) 2. The method of embodiment 1, wherein the solvent is added as a mixture containing additional sulfide solid electrolyte and / or active material particles. (Aspect 3) 3. The method of embodiment 1 or 2, comprising alternately repeating step (a) and step (b). (Aspect 4) The method according to any one of Aspects 1 to 3, wherein the active material particles are pre-coated active material particles with at least a part of the surface pre-coated with a solid electrolyte for coating. (Aspect 5) The method according to Aspect 4, wherein the solid electrolyte for coating is a fluorine-containing solid electrolyte. (Aspect 6) The solid electrolyte for coating is Li 6-(4-x)b (Ti 1-x Al x ) b F6 (0 < x < 1, 0 < b ≤ 1.5), the method according to Aspect 5. (Aspect 7) A method for manufacturing a battery, comprising the following steps: Manufacturing an electrode composite powder by the method according to any one of Aspects 1 to 6, and Forming an active material layer containing the electrode composite powder.

Advantages of the Invention

[0012] According to the method of the present disclosure, when kneading the active material particles and the sulfide solid electrolyte, an excessive load on the device can be suppressed.

Brief Description of the Drawings

[0013] [Figure 1] Figure 1 is a diagram showing the relationship between the vertical stress and the shear stress in a plurality of kneaded materials having a predetermined NV. [Figure 2] Figure 2 is a diagram showing the relationship between NV and the slope of the shear stress.

Embodiments for Carrying out the Invention

[0014] ≪Method for Manufacturing Electrode Composite Powder≫ The method of the present disclosure for manufacturing an electrode composite powder is (a) Kneading the active material particles and the sulfide solid electrolyte while adding a solvent, and (b) after step (a), kneading the active material particles and the sulfide solid electrolyte without adding a solvent to at least partially deform the sulfide solid electrolyte and coat at least a portion of the surface of the active material particles with the sulfide solid electrolyte; and The kneading speed in step (a) is lower than the kneading speed in step (b), and The electrode composite powder includes the active material particles and the sulfide solid electrolyte.

[0015] According to the above-described method for producing an electrode composite powder, excessive load on the apparatus can be suppressed when the active material particles and the sulfide solid electrolyte are kneaded.

[0016] In conventional methods, a solvent is added without kneading the active material particles and the sulfide solid electrolyte, and then the active material particles and the sulfide solid electrolyte are kneaded after the solvent is added. In this process, the solvent is locally distributed in the active material particles and the sulfide solid electrolyte. The stress required for kneading the sulfide solid electrolyte varies depending on the nonvolatile content, i.e., the ratio of the solvent contained. Therefore, the localization of the solvent may impose an excessive mechanical load on the kneading device.

[0017] In contrast, according to the method of the present disclosure, in step (a), the solvent is added while mixing at a relatively slow speed. This ensures that the solid phase components (active material particles and sulfide solid electrolyte) and the solvent are mixed together in step (a), while preventing excessive mechanical load from being applied to the mixing device.

[0018] Furthermore, according to the method of the present disclosure, in step (b) performed after step (a), kneading is performed at a relatively high speed without adding a solvent. This makes it possible to suppress localization of the solvent due to the addition of the solvent and the resulting excessive mechanical load on the kneading device, while quickly deforming the sulfide solid electrolyte and coating the surfaces of the active material particles with the sulfide solid electrolyte.

[0019] The relationship between normal stress and shear stress for multiple kneaded materials with a given NV is shown in Figure 1. A steep shear stress gradient indicates that the applied shear stress increases when a large stress is applied, i.e., a greater mechanical load is placed on the kneading device. The shear stress gradient of the kneaded material changes depending on the NV value of the kneaded material. In this disclosure, the shear stress gradient represents the magnitude of the change in shear stress relative to the change in normal stress of the kneaded material.

[0020] The relationship between the slope of the shear stress and a predetermined NV in FIG. 1 is shown in FIG. 2. In a kneaded material containing a sulfide solid electrolyte, the slope of the shear stress becomes particularly large when the NV reaches a predetermined value. Therefore, when a solvent is added to the active material particles and the sulfide solid electrolyte to reduce the NV, the slope of the shear stress increases (i.e., the mechanical load on the kneading device increases) until the NV reaches a predetermined value (until the NV reaches approximately 78.5 in the case of FIG. 2). The sample shown in FIG. 1 has the following configuration.

[0021] 1: Sulfide solid electrolyte (SE) + Li 2.7 Ti 0.3 Al 0.7 F6 coated Li(NiCoAl)O2 (LTAF coated NCA), NV=78% 2: SE+LTAF-covered NCA, NV=79% 3: SE+LTAF-covered NCA, NV=81% 4: SE+LTAF-covered NCA, NV=82% 5: SE+LTAF-covered NCA, NV=84% 6: SE+LTAF-covered NCA, NV=86% 7: SE+LTAF-covered NCA, NV=88%

[0022] Hereinafter, embodiments of the present disclosure will be described in detail. Note 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.

[0023] <Process (a)> In the method of the present disclosure, first, the active material particles and the sulfide solid electrolyte are kneaded while adding a solvent.

[0024] In the method of the present disclosure, the solvent may be added as a mixture containing the additional sulfide solid electrolyte and / or the active material particles, and in this case, the solvent and the additional sulfide solid electrolyte and / or the active material particles may be mixed in advance using an ultrasonic homogenizer.

[0025] In the method of the present disclosure, the kneading speed in step (a) is lower than the kneading speed in step (b). Specifically, for example, the difference between the kneading speed in step (a) and the kneading speed in step (b) may be 5 rpm or more, 10 rpm or more, 20 rpm or more, 30 rpm or more, or 35 rpm or more, and may be 100 rpm or less, 80 rpm or less, 60 rpm or less, or 50 rpm or less. In the present disclosure, the kneading speed in step (a) may be 10 rpm or more, 20 rpm or more, or 30 rpm or more, and may be 80 rpm or less, 70 rpm or less, or 60 rpm or less.

[0026] In the method of the present disclosure, the kneading in step (a) can be carried out in a low dew point environment, for example, an environment in which the dew point temperature is 0°C or lower, -30°C or lower, -50°C or lower, or -70°C or lower.

[0027] In the method of the present disclosure, the kneading in step (a) is a firm kneading. In the method of the present disclosure, any kneading device can be used as long as it is capable of firm kneading. For example, a planetary mixer or the like may be used as the kneading device. The method of the present disclosure can be carried out using a planetary mixer or the like as the kneading device.

[0028] In the method of the present disclosure, the kneading time in step (a) can be selected arbitrarily within a range that can prevent localization of the solvent due to the addition of the solvent and the resulting excessive mechanical load on the kneading device.

[0029] <Process (b)> In the method of the present disclosure, the active material particles and the sulfide solid electrolyte are then kneaded without adding a solvent to at least partially deform the sulfide solid electrolyte and coat at least a portion of the surface of the active material particles with the sulfide solid electrolyte.

[0030] In the present disclosure, the kneading speed in step (b) may be 50 rpm or more, 60 rpm or more, or 70 rpm or more, and may be 110 rpm or less, 100 rpm or less, or 90 rpm or less.

[0031] In the method of the present disclosure, the kneading time in step (b) can be selected arbitrarily within a range that allows the sulfide solid electrolyte and the active material particles to be sufficiently kneaded.

[0032] In the method of the present disclosure, the kneading in step (b) can be carried out in a low dew point environment, for example, an environment in which the dew point temperature is 0°C or lower, -30°C or lower, -50°C or lower, or -70°C or lower.

[0033] In the method of the present disclosure, the kneading in step (b) can be carried out using a planetary mixer or the like as a kneading device.

[0034] In the method of the present disclosure, step (a) and step (b) may be alternately repeated. This allows the solvent to be added in multiple divided portions. If the solvent is not added in multiple divided portions and the final amount of liquid is added all at once, the kneaded material may liquefy. If the kneaded material liquefies, the kneading may not be maintained, and the desired coating process may not be completed.

[0035] <Battery manufacturing method> The method for manufacturing a battery in the present disclosure includes the following steps: Producing an electrode composite powder by the method described herein; and forming an active material layer containing the electrode composite powder;

[0036] The active material layer of the battery produced by the method of the present disclosure may be provided by a composite slurry containing an electrode composite powder and a dispersing medium, and the active material layer may be formed by applying the composite slurry to a substrate and then drying and removing the dispersing medium.

[0037] ≪Each configuration≫ Each component used in the method of the present disclosure will be described below.

[0038] (electrode composite powder) In the present disclosure, the electrode composite powder includes active material particles and a sulfide solid electrolyte.

[0039] (active material particles) In the present disclosure, active material particles are contained in an electrode composite powder and are coated with a sulfide solid electrolyte by the method of the present disclosure.

[0040] In the present disclosure, the "active material particles" may be either "positive electrode active material" or "negative electrode active material."

[0041] The active material particles are not particularly limited, but may be pre-coated active material particles having a coating layer made of a coating solid electrolyte. The coating layer is a layer containing a substance that has lithium ion conductivity, low reactivity with the active material particles and the solid electrolyte, and can maintain the shape of the coating layer without flowing even when in contact with the active material particles and the solid electrolyte. Specific examples of the coating solid electrolyte include LiNbO3 and Li4Ti5O 12 , Li3PO4, Li 2.7 Ti 0.3 Al 0.7 In particular, the solid electrolyte for coating may be a fluorine-containing solid electrolyte, such as Li 2.7 Ti 0.3 Al 0.7 LTAF electrolytes such as F6 (Li 6-(4-x)b (Ti 1-x Al x ) bWhen F6(0 < x < 1, 0 < b ≤ 1.5)), the solvent and the preliminary coating active material particles are not easily compatible, whereby the solvent is locally distributed and an excessive mechanical load is likely to be applied to the kneading apparatus, so the method of the present disclosure can be effectively used.

[0042] (Positive electrode active material) The material of the positive electrode active material is not particularly limited. Examples of the positive electrode active material include lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganate (LiMn2O4), lithium nickel cobalt manganate (NCM: LiCO 1 / 3 Ni 1 / 3 Mn 1 / 3 O2), lithium nickel cobalt aluminum oxide (LiNi 0.8 (CoAl) 0.2 O2), Li 1+x Mn 2-x-y M y O4 (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn), and may be a heterogeneous element-substituted Li-Mn spinel having a composition represented by this, but is not limited thereto.

[0043] (Active material) The active material is the core of the electrode composite powder. The active material is in the form of particles. The active material may be, for example, secondary particles. The secondary particles are an aggregate of primary particles. The D 50 of the secondary particles may be, for example, 1 to 30 μm, 3 to 20 μm, or 5 to 15 μm. The average Feret diameter of the primary particles may be, for example, 0.01 to 3 μm.

[0044] The active material can have any shape. The active material may be, for example, spherical, ellipsoidal, flake-shaped, or fibrous. The active material may be solid particles or hollow particles. Note that the average particle diameter D 50 is the particle diameter (median diameter) at 50% of the integrated value in the volume-based particle size distribution determined by the laser diffraction / scattering method.

[0045] (Negative electrode active material) The material of the negative electrode active material is not particularly limited, and may be metallic lithium or a material capable of absorbing and releasing metal ions such as lithium ions. Examples of materials capable of absorbing and releasing metal ions such as lithium ions include alloy-based negative electrode active materials, carbon materials, and lithium titanate (Li4Ti5O 12 ) and the like can be mentioned, but are not limited to these.

[0046] The alloy-based negative electrode active material is not particularly limited, and examples thereof include Si alloy-based negative electrode active materials and Sn alloy-based negative electrode active materials. Si alloy-based negative electrode active materials include silicon, silicon oxide, silicon carbide, silicon nitride, etc., or solid solutions thereof. Si alloy-based negative electrode active materials can also include metal elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. Sn alloy-based negative electrode active materials can also include tin, tin oxide, tin nitride, etc., or solid solutions thereof. Sn alloy-based negative electrode active materials can also include metal elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc.

[0047] The carbon material is not particularly limited, and examples thereof include hard carbon, soft carbon, graphite, and the like.

[0048] The negative electrode active material is in the form of particles. The negative electrode active material may be in the form of primary particles or secondary particles formed by agglomeration of a plurality of primary particles. The average particle diameter D of the negative electrode active material 50 The average particle size D may be, for example, 1 nm or more, 5 nm or more, or 10 nm or more, and may be 500 μm or less, 100 μm or less, 50 μm or less, or 30 μm or less. 50 is the particle size (median size) at 50% cumulative value in the volume-based particle size distribution determined by laser diffraction / scattering method.

[0049] (Sulfide solid electrolyte) In the present disclosure, the sulfide solid electrolyte is contained in the electrode composite powder.

[0050] The sulfide solid electrolyte is attached to the surface of the active material particles together with the solvent. The sulfide solid electrolyte may coat the surface of the active material particles. The sulfide solid electrolyte is in a particulate form. 50 The particle size may be, for example, 0.01 to 1 μm or 0.1 to 0.9 μm. The amount of the sulfide solid electrolyte to be blended may be, for example, 0.1 to 20 parts by mass or 0.5 to 15 parts by mass per 100 parts by mass of the active material.

[0051] Examples of sulfide solid electrolytes include, but are not limited to, sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, and argyrodite-type solid electrolytes. Examples of sulfide solid electrolytes include Li2S-P2S5-based (Li7P3S 11 , Li3PS4, Li8P2S9, etc.), Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-LiBr-Li2S-P2S5, Li2S-P2S5-GeS2 (Li 13 GeP3S 16 , Li 10 GeP2S 12 ), LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li 7-x PS 6-x Cl x These may include, but are not limited to, the following:

[0052] The sulfide solid electrolyte may be glass or crystallized glass (glass ceramics).

[0053] (solvent) In the present disclosure, the solvent is added while the active material particles and the sulfide solid electrolyte are being kneaded.

[0054] The solvent is a liquid. The solvent can promote adhesion between the active material particles and the sulfide solid electrolyte during kneading. The solvent can function as a dispersion medium in the slurry. The solvent can contain any component. For example, the solvent may contain at least one selected from the group consisting of aromatic hydrocarbons, esters, alcohols, ketones, and lactams. For example, the solvent may contain at least one selected from the group consisting of tetralin (1,2,3,4-tetrahydronaphthalene, THN), butyl butyrate, heptane, and N-methyl-2-pyrrolidone (NMP).

[0055] Butyl butyrate is expected to be less likely to deteriorate the sulfide solid electrolyte than, for example, NMP, etc. THN is expected to be less likely to deteriorate the sulfide solid electrolyte than, for example, butyl butyrate and NMP, etc. When the solvent contains THN, for example, it is expected that the initial resistance will be reduced.

[0056] 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. [Example]

[0057] Hereinafter, an electrode composite powder was produced according to the production method of the embodiment, and the average power consumption and maximum power consumption of the device during production were investigated.

[0058] (Preparation of Pre-Coated Active Material Particles) As the active material, Li(NiCoAl)O2 was prepared. This active material may be abbreviated as "NCA" hereinafter.

[0059] A fluoride solid electrolyte was synthesized as a coating solid electrolyte by mixing LiF, TiF4, and AlF3 in a planetary ball mill. 2.7 Ti 0.3 Al 0.7 F6. This fluoride solid electrolyte may be hereinafter abbreviated as "LTAF."

[0060] A "Nobilta NOB-MINI (manufactured by Hosokawa Micron Corporation)" was used as an apparatus for pre-coating the active material particles. In this apparatus, 48.7 parts by mass of NCA and 1.3 parts by mass of LTAF were kneaded to form pre-coated active material particles. The operating conditions of the apparatus are as follows:

[0061] Power: 12W per gram of material Rotation speed: 6000 rpm Processing time: 30 minutes

[0062] (Other ingredients) For the examples of this disclosure, the following materials were prepared: Sulfide solid electrolyte: Li2S-P2S5 (glass ceramics) Solvent:THN "Li2S-P2S5" may be abbreviated as "LPS" hereinafter.

[0063] Example 1 The subsequent operations were carried out in an environment where the dew point temperature was controlled to -70°C or below. An ultrasonic homogenizer was used as the dispersion device. The sulfide solid electrolyte was dispersed in the solvent using the ultrasonic homogenizer to prepare a dispersion liquid.

[0064] A planetary mixer was used as the kneading device, and the pre-coated active material particles obtained in the above preparation were supplied to the kneading device.

[0065] An electrode composite powder was produced by performing "kneading" and "adding solvent during kneading" in the following order of steps (0) to (4). In the "adding solvent during kneading" step, the solvent was added with a dropper while kneading the pre-coated active material particles and the sulfide solid electrolyte. An evaluation sample according to Example 1 was thus obtained, which was an electrode composite powder in which the pre-coated active material particles were coated with the sulfide solid electrolyte.

[0066] (0) Preparation for kneading (supplying dispersion liquid to pre-coated active material particles): No kneading (1) Mixing: Low mixing speed (2) Add solvent during kneading: kneading speed slow (3) Mixing: Mixing speed: Medium (4) Mixing: High mixing speed

[0067] Example 2 An evaluation sample according to Example 2, which is an electrode composite powder, was obtained in the same manner as in Example 1, except that the LTAF described in Example 1 was replaced with LiNbO3.

[0068] Example 3 An evaluation sample according to Example 3, which is an electrode composite powder, was obtained in the same manner as in Example 1, except that the above procedure was replaced with the following.

[0069] (0) Preparation for kneading (supplying dispersion liquid to pre-coated active material particles): No kneading (1) Mixing: Low mixing speed (2) Add solvent during kneading: kneading speed slow (3) Mixing: Mixing speed: Medium (4) Add solvent during kneading: kneading speed slow (5) Mixing: Mixing speed: Medium (6) Mixing: High mixing speed

[0070] Example 4 An evaluation sample according to Example 4, which is an electrode composite powder, was obtained in the same manner as in Example 1, except that the above procedure was replaced with the following.

[0071] (0) Preparation for kneading (supplying dispersion liquid to pre-coated active material particles): kneading speed: low (1) Mixing: Low mixing speed (2) Add solvent during kneading: kneading speed slow (3) Mixing: Mixing speed: Medium (4) Mixing: High mixing speed

[0072] Comparative Example 1 The subsequent operations were carried out in an environment where the dew point temperature was controlled to -70°C or lower. An ultrasonic homogenizer was used as a dispersion device. 98.4 parts by mass of the sulfide solid electrolyte was dispersed in 229.6 parts by mass of a solvent using the ultrasonic homogenizer to prepare a dispersion liquid.

[0073] A planetary mixer was used as the kneading device, and 1000 parts by mass of the pre-coated active material particles obtained in the above preparation were supplied to the kneading device.

[0074] An electrode composite powder was produced by performing "kneading" and "addition of solvent" in the following order of steps (0) to (3). When kneading was performed at 100 rpm for 10 minutes in the below-described "(3) kneading", the kneaded material liquefied and could not be kneaded, and the pre-coated active material particles could not be coated with the sulfide solid electrolyte.

[0075] (0) Preparation for kneading (supplying dispersion liquid to pre-coated active material particles): No kneading (1) Mixing: Mixing speed 70 rpm (2) Addition of solvent: No kneading (3) Mixing: Mixing speed 100 rpm

[0076] Comparative Example 2 An evaluation sample according to Comparative Example 2, which is an electrode composite powder, was obtained in the same manner as Comparative Example 1, except that the above procedure was replaced by the following.

[0077] (0) Preparation for kneading (supplying dispersion liquid to pre-coated active material particles): No kneading (1) Mixing: Mixing speed 70 rpm (2) Addition of solvent: No kneading (3) Mixing: Mixing speed 100 rpm (4) Addition of solvent: No kneading (5) Mixing: Mixing speed 100 rpm (6) Addition of solvent: No kneading (7) Mixing: Mixing speed 100 rpm

[0078] <Evaluation> Table 1 shows the average and maximum power consumption of the devices used to produce electrode composite powders using the methods described in Examples 1 to 4 and Comparative Examples 1 and 2. As is clear from Table 1, the average and maximum power consumption of Examples 1 to 4 was lower than those of Comparative Examples 1 and 2. This means that the load on the device was smaller. Therefore, by using the method of the present disclosure, it was possible to produce an electrode composite powder by kneading pre-coated active material particles and a sulfide solid electrolyte while suppressing excessive load on the device.

[0079] [Table 1]

Claims

1. A method for producing an electrode composite powder, comprising: (a) kneading the active material particles and the sulfide solid electrolyte while adding a solvent; and (b) after step (a), kneading the active material particles and the sulfide solid electrolyte without adding a solvent to at least partially deform the sulfide solid electrolyte and coat at least a portion of the surface of the active material particles with the sulfide solid electrolyte; and The kneading speed in step (a) is lower than the kneading speed in step (b), and the electrode composite powder includes the active material particles and the sulfide solid electrolyte; Manufacturing method of electrode composite powder.

2. The method of claim 1 , wherein the solvent is added as a mixture containing additional sulfide solid electrolyte and / or active material particles.

3. The method of claim 1 , comprising alternatingly repeating steps (a) and (b).

4. The method according to claim 1 , wherein the active material particles are pre-coated active material particles, at least a portion of the surface of which is pre-coated with a coating solid electrolyte.

5. The method of claim 4, wherein the coating solid electrolyte is a fluorine-containing solid electrolyte.

6. The solid electrolyte for coating is Li ６－（４－ｘ）ｂ (Ti １－ｘ Al ｘ ) ｂ F ６ 6. The method of claim 5, wherein (0<x<1, 0<b≦1.5).

7. A method for manufacturing a battery, comprising the steps of: Producing an electrode composite powder by the method according to any one of claims 1 to 6, and forming an active material layer containing the electrode composite powder;

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