Sulfide-based inorganic solid electrolyte material, solid electrolyte membrane, all-solid-state lithium-ion battery, apparatus for manufacturing sulfide-based inorganic solid electrolyte material, and method for manufacturing sulfide-based inorganic solid electrolyte material

Abstract

A sulfide-based inorganic solid electrolyte material having a particle diameter d50 of 0.1 μm or more and 100 μm or less when the cumulative frequency is 50% in the volume-based cumulative frequency distribution curve measured using a laser diffraction scattering particle size distribution measuring device, and having an adhesion area of ​​10% or less as measured according to the method below. (method) (1) A SUS304 plate measuring 8 cm in length × 9 cm in width is installed such that the vertical side is tangent to the horizontal plane and the inclination is 45° with respect to the horizontal plane. The arithmetic mean roughness Ra measured according to JIS B 0601 (2013) is 0.017 μm or more and 0.023 μm or less, the maximum height Rz is 0.14 μm or more and 0.18 μm or less, and the ten-point average roughness Rzjis is 0.12 μm or more and 0.16 μm or less. (2) Using a sieve with a mesh size of 250 μm, 10 g of sulfide-based inorganic solid electrolyte material is dropped onto a SUS304 plate from a height of 10 cm from the horizontal plane so that the entire SUS304 plate is covered with sulfide-based inorganic solid electrolyte material. (3) Drop one 47 g zirconia ball from a height of 5 cm from the top of the SUS304 plate three times, ensuring that it only touches the top of the SUS304 plate and does not touch the surface of the SUS304 plate to which the sulfide-based inorganic solid electrolyte material is attached. (4) Measure the area of ​​the sulfide-based inorganic solid electrolyte material attached to the surface of the SUS304 plate after impact, and calculate the ratio (attachment area) to the area of ​​one side of the SUS304 plate.

Description

Technology Field

[0001] The present invention relates to a sulfide-based inorganic solid electrolyte material, a solid electrolyte membrane, an all-solid-state lithium-ion battery, an apparatus for manufacturing a sulfide-based inorganic solid electrolyte material, and a method for manufacturing a sulfide-based inorganic solid electrolyte material. Background Technology

[0002] Lithium-ion batteries are generally used as power sources for small portable devices such as mobile phones and laptops. In addition, recently, lithium-ion batteries have begun to be used as power sources for electric vehicles and power storage, in addition to small portable devices.

[0003] Currently commercially available lithium-ion batteries use electrolytes containing flammable organic solvents. On the other hand, lithium-ion batteries that have been solidified by replacing the electrolyte with a solid electrolyte (hereinafter also referred to as all-solid-state lithium-ion batteries) do not use flammable organic solvents within the battery, which allows for the simplification of safety devices and is considered to offer superior manufacturing costs and productivity.

[0004] Recently, solid electrolyte membranes primarily comprising sulfide solid electrolyte materials are sometimes used as solid electrolyte materials for such lithium-ion batteries. For example, lithium sulfide (Li2S) and phosphorus pentasulfide (P2S5) are used as the main components of sulfide-based inorganic solid electrolyte materials.

[0005] Patent Document 1 (Japanese Patent Publication No. 2016-27545) describes a structure having a peak at the position 2θ = 29.86° ± 1.00° in X-ray diffraction measurements using CuKα rays, Li 2y＋3 A sulfide-based solid electrolyte material is described, characterized by having a composition of PS4 (0.1≤y≤0.175).

[0006] In addition, P2S5 is a highly reactive, unstable ionic crystalline powder that transitions to a stable state through the chemical reaction with Li2S via mechanical milling. During the process of reaching this stable state, it adheres to and deposits on the inner wall of the device. As a technology to prevent adhesion and deposition during the manufacturing process of such powder, various conventional measures have been taken, including, for example, blast treatment that creates fine irregularities on the surface as described in the patent document below.

[0007] Patent Document 2 (Japanese Patent Publication No. 2017-119902) describes a titanium member that inhibits powder adhesion, characterized in that the arithmetic mean roughness (Ra) of a surface layer having an uneven surface in contact with a powder is 0.4 μm or more and 2.0 μm or less, and the Vickers hardness of the surface layer is 400 or more. In addition, as the powders handled, silver particles with a median diameter of 1.5 μm, nickel particles with a median diameter of 2.5 μm, powder coating with a median diameter of 23 μm, and alumina with a median diameter of 8 μm are cited as examples in the examples.

[0008] Patent document 3 (Japanese Patent Publication No. 2017-128101) describes a powder adhesion inhibiting member characterized by having a coating having an uneven surface in contact with a powder, wherein the arithmetic mean roughness (Ra) of the uneven surface is 0.2 μm or more and 1.6 μm or less, and the Vickers hardness of the coating is 400 or more. In addition, as the powders to be handled, silver particles with a median diameter of 1.5 μm, copper particles with a median diameter of 22.3 μm, PTFE particles with a median diameter of 0.3 μm, and alumina particles with a median diameter of 8 μm are cited as examples in the examples. Prior art literature

[0009] Japanese Patent Publication No. 2016-27545, Japanese Patent Publication No. 2017-119902, Japanese Patent Publication No. 2017-128101 The problem to be solved

[0010] However, in conventional technology, it was found that there was a variation in lithium ion conductivity depending on the manufacturing batch of the sulfide-based inorganic solid electrolyte material obtained. In addition, it was found that in the manufacturing apparatus for sulfide-based inorganic solid electrolyte material, blast treatment to create fine irregularities on the inner surface of the apparatus was ineffective, and powder adhered and deposited on the inner wall surface of the apparatus.

[0011] The present invention has been made in consideration of these circumstances and aims to provide a sulfide-based inorganic solid electrolyte material, a solid electrolyte membrane, and an all-solid-state lithium-ion battery that maintains handling properties and lithium-ion conductivity while minimizing variation in lithium-ion conductivity between manufacturing batches. Furthermore, the invention aims to provide an apparatus for manufacturing a sulfide-based inorganic solid electrolyte material and a method for manufacturing the sulfide-based inorganic solid electrolyte material, which prevents the adhesion and deposition of powder onto the inner wall surface of the device, thereby enabling improved recovery yield during manufacturing and uniformity of physical properties of the product. means of solving the problem

[0012] The inventors have carefully examined the problem to solve it. As a result, they discovered that when a sulfide-based inorganic solid electrolyte material is screened onto a smooth metal plate, it is difficult for the sulfide-based inorganic solid electrolyte material to adhere to the metal plate, thereby reducing the variation in lithium ion conductivity between manufacturing batches while maintaining handling properties and lithium ion conductivity, and that it is possible to stably obtain a sulfide-based inorganic solid electrolyte material having high lithium ion conductivity. Additionally, they discovered that by making the inner wall surface of the device a smooth surface with a small arithmetic mean roughness, it is possible to prevent the adhesion and deposition of powder onto the inner wall surface of the device, and thus arrived at the present invention.

[0013] That is, according to the present invention, the following sulfide-based inorganic solid electrolyte material, solid electrolyte membrane, all-solid-state lithium-ion battery, apparatus for manufacturing the sulfide-based inorganic solid electrolyte material, and method for manufacturing the sulfide-based inorganic solid electrolyte material are provided.

[0014] [1]

[0015] Particle diameter d at a cumulative frequency of 50% in the volume-based cumulative frequency distribution curve measured using a laser diffraction scattering particle size distribution measuring device 50 As a sulfide-based inorganic solid electrolyte material having a thickness of 0.1 μm or more and 100 μm or less,

[0016] Attachment area of ​​10% or less as measured according to the (method) below,

[0017] Sulfide-based inorganic solid electrolyte material.

[0018] (method)

[0019] (1) A SUS304 plate measuring 8 cm in length × 9 cm in width is installed such that the vertical side is tangent to the horizontal plane and the inclination is 45° with respect to the horizontal plane. The arithmetic mean roughness Ra measured according to JIS B 0601 (2013) is 0.017 μm or more and 0.023 μm or less, the maximum height Rz is 0.14 μm or more and 0.18 μm or less, and the ten-point average roughness Rzjis is 0.12 μm or more and 0.16 μm or less.

[0020] (2) Using a sieve with a mesh size of 250 μm, 10 g of sulfide-based inorganic solid electrolyte material is dropped onto the SUS304 plate from a height of 10 cm from the horizontal plane, so that the entire SUS304 plate is covered with the sulfide-based inorganic solid electrolyte material.

[0021] (3) One 47 g zirconia ball is dropped three times from a height of 5 cm from the top of the SUS304 plate, so that it only touches the top of the SUS304 plate and does not touch the surface of the SUS304 plate to which the sulfide-based inorganic solid electrolyte material is attached.

[0022] (4) Measure the area of ​​the surface of the SUS304 plate to which the sulfide-based inorganic solid electrolyte material is attached after impact, and calculate the ratio (attachment area) to the area of ​​one side of the SUS304 plate.

[0023] [2]

[0024] As a sulfide-based inorganic solid electrolyte material as described in [1] above,

[0025] Sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements.

[0026] [3]

[0027] As a sulfide-based inorganic solid electrolyte material as described in [2] above,

[0028] A sulfide-based inorganic solid electrolyte material wherein the molar ratio of the content of Li to the content of P (Li / P) is 1.0 or more and 10.0 or less, and the molar ratio of the content of S to the content of P (S / P) is 1.0 or more and 10.0 or less.

[0029] [4]

[0030] As a sulfide-based inorganic solid electrolyte material described in any one of [1] to [3] above,

[0031] The lithium ion conductivity measured by the AC impedance method under measurement conditions of 27.0℃, applied voltage of 10 mV, and a measurement frequency range of 0.1 Hz to 7 MHz is 1.0 × 10⁻⁶ －4 S·cm －1 Lee Sang-in, sulfide-based inorganic solid electrolyte material.

[0032] [5]

[0033] A solid electrolyte membrane comprising a sulfide-based inorganic solid electrolyte material described in any one of [1] to [4] above.

[0034] [6]

[0035] A solid-state lithium-ion battery comprising a positive electrode including a positive active material layer, an electrolyte layer, and a negative electrode including a negative active material layer,

[0036] A full-solid-state lithium-ion battery comprising at least one of the positive electrode active material layer, the electrolyte layer, and the negative electrode active material layer, wherein the sulfide-based inorganic solid electrolyte material described in any one of [1] to [4].

[0037] [7]

[0038] As an apparatus for manufacturing sulfide-based inorganic solid electrolyte materials,

[0039] A blower unit that sends inert gas,

[0040] A grinding unit that repeatedly vitrifies a plurality of inorganic compounds serving as the sulfide-based inorganic solid electrolyte material by mechanical energy, and blows up the vitrified plurality of inorganic compounds by the inert gas sent from the blower unit,

[0041] A first recovery unit into which at least a portion of the plurality of inorganic compounds blown up by the inert gas enters, and which returns the at least a portion of the plurality of inorganic compounds toward the grinding unit, and

[0042] A system for circulating the inert gas from the blower unit through the crusher unit and the first recovery unit to the blower unit.

[0043] As a device equipped with,

[0044] A device having an arithmetic mean roughness Ra of 0.02 μm or less, measured according to JIS B 0601 (2013) on the inner wall surface of the grinding section above.

[0045] [8]

[0046] In the device described in [7] above,

[0047] A device having a maximum height Rz of 0.16 μm or less, measured according to JIS B 0601 (2013) on the inner wall surface of the above-mentioned grinding section.

[0048] [9]

[0049] In the device described in [7] or [8] above,

[0050] A device having a ten-point average roughness Rzjis of the inner wall surface of the grinding section measured according to JIS B 0601 (2013) of 0.14 μm or less.

[0051]

[10]

[0052] In any one of [7] to [9] above,

[0053] A first receiving portion for receiving the plurality of inorganic compounds supplied to the grinding portion,

[0054] A first pipe leading to the first recovery section and the first receiving section, and

[0055] A first valve detachably mounted to the first pipe together with the first receiving portion.

[0056] A device additionally equipped with

[0057]

[11]

[0058] In the device described in

[10] above,

[0059] A device further comprising a first line for introducing an inert gas into the first pipe.

[0060]

[12]

[0061] In any one of the above [7] to

[11] devices,

[0062] A second recovery section into which the sulfide-based inorganic solid electrolyte material, blown up by the inert gas, enters

[0063] A second pipe leading to the crushing section and the first recovery section,

[0064] A second valve installed in the second pipe above,

[0065] A portion of the second pipe located between the crushing section and the second valve, and a third pipe leading to the second recovery section, and

[0066] The third valve installed in the third pipe above

[0067] A device additionally equipped with

[0068]

[13]

[0069] In the device described in

[12] above,

[0070] A second receiving section for receiving the sulfide-based inorganic solid electrolyte material recovered by the second recovery section,

[0071] A fourth pipe leading to the second recovery section and the second receiving section, and

[0072] A second line introducing inert gas into the above-mentioned fourth pipe

[0073] A device additionally equipped with

[0074]

[14]

[0075] In any one of the above [7] to

[13] devices,

[0076] A fifth pipe connecting the blower unit and the grinding unit,

[0077] The fifth valve installed in the above fifth pipe,

[0078] A sixth pipe for returning at least a portion of the plurality of inorganic compounds from the first recovery unit toward the grinding unit, and

[0079] The 6th valve installed in the above 6th pipe

[0080] A device additionally equipped with

[0081]

[15]

[0082] In the device described in

[14] above,

[0083] A device having an arithmetic mean roughness Ra of the inner wall surface of the device, measured according to JIS B 0601 (2013), of 0.02 μm or less in one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe.

[0084]

[16]

[0085] In the device described in

[14] or

[15] above,

[0086] A device in which the maximum height Rz measured according to JIS B 0601 (2013) of the inner wall surface of the device in one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe is 0.16 μm or less.

[0087]

[17]

[0088] In any one of the above

[14] to

[16] devices,

[0089] A device having a ten-point average roughness Rzjis measured according to JIS B 0601 (2013) of the inner wall surface of one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe, which is 0.14 μm or less.

[0090]

[18]

[0091] In any one of the above [7] to

[17] devices,

[0092] A device further comprising a pressure reducing unit that reduces the internal pressure of the grinding unit.

[0093]

[19]

[0094] In any one of the above [7] to

[18] devices,

[0095] The above grinding unit is a device having a rotary table, a plurality of balls arranged around a rotation axis of the rotary table and each rotatably about a rotation axis that rotates together with the rotation of the rotary table, and a pressing unit that presses the plurality of balls toward the rotary table from the opposite side.

[0096]

[20]

[0097] In any one of the above [7] to

[19] devices,

[0098] The above-mentioned grinding section is a device having a cover section that directs the flow of the inert gas, which sprays the plurality of types of inorganic compounds, toward the center of the grinding section and the lower part of the grinding section.

[0099]

[21]

[0100] In any one of the above [7] to

[20] devices,

[0101] The above-mentioned plurality of inorganic compounds is a device containing the element Li.

[0102]

[22]

[0103] As a method for manufacturing sulfide-based inorganic solid electrolyte materials,

[0104] Process (A): A process for preparing an inorganic composition comprising two or more inorganic compounds that are raw materials, and

[0105] Process (B): A process of obtaining a sulfide-based inorganic solid electrolyte material by mechanically treating an inorganic composition to chemically react the raw inorganic compounds with each other while vitrifying the inorganic composition.

[0106] A method for manufacturing a sulfide-based inorganic solid electrolyte material comprising,

[0107] The above process (B)

[0108] Sending inert gas by means of a blower,

[0109] The process of vitrifying a plurality of inorganic compounds that serve as the sulfide-based inorganic solid electrolyte material by mechanical energy, and repeating the process of blowing up the vitrified plurality of inorganic compounds by the inert gas sent from the blower unit by the grinding unit,

[0110] Returning at least a portion of the plurality of inorganic compounds that are blown up by the inert gas and enter the first recovery unit from the first recovery unit toward the grinding unit, and

[0111] Circulating the inert gas from the blower unit through the crusher unit and the first recovery unit to the blower unit.

[0112] A method for manufacturing a sulfide-based inorganic solid electrolyte material comprising

[0113]

[23]

[0114] As a method for manufacturing a sulfide-based inorganic solid electrolyte material as described in

[23] above,

[0115] Process (C): A process of crushing, classifying, or granulating the obtained sulfide-based inorganic solid electrolyte material.

[0116] A method for manufacturing a sulfide-based inorganic solid electrolyte material further comprising Effects of the invention

[0117] According to the present invention, it is possible to provide a sulfide-based inorganic solid electrolyte material, a solid electrolyte membrane, and an all-solid-state lithium-ion battery that maintain handling properties and lithium-ion conductivity while having low variation in lithium-ion conductivity per manufacturing batch. Furthermore, it is possible to provide an apparatus for manufacturing a sulfide-based inorganic solid electrolyte material and a method for manufacturing a sulfide-based inorganic solid electrolyte material that enables improved recovery yield during manufacturing and homogenization of physical properties of the product. Brief explanation of the drawing

[0118] FIG. 1 is a drawing showing the apparatus of the present embodiment. Figure 2 is a top view of the rotary table and a plurality of balls of the grinding unit shown in Figure 1. Figure 3 is a cross-sectional view of A-A´ in Figure 2. Figure 4 is a drawing showing a variation of Figure 3. FIG. 5 is a cross-sectional view showing an example of the structure of an electrode for an all-solid-state lithium-ion battery according to the present embodiment. FIG. 6 is a schematic diagram showing the sieve test and the measurement test of the attachment area of ​​the present embodiment. FIG. 7 is a schematic diagram showing the sieve test, pressing test, and attachment area measurement test of the present embodiment. FIG. 8 is a schematic diagram showing the pressing test of the present embodiment. FIG. 9 is a schematic diagram showing the pressing test of the present embodiment. FIG. 10 is a drawing showing the measurement results of the attachment area of ​​the present embodiment. Specific details for implementing the invention

[0119] Embodiments of the present invention are described below using drawings. The drawings are schematic and do not necessarily correspond to actual dimensional ratios. Furthermore, in this embodiment, unless otherwise specified, a layer formed by a positive electrode material is called a positive electrode active material layer, and a positive electrode formed by forming a positive electrode active material layer on a current collector is called a positive electrode. Additionally, a layer formed by a negative electrode material is called a negative electrode active material layer, and a negative electrode formed by forming a negative electrode active material layer on a current collector is called a negative electrode.

[0120] [Sulfide-based inorganic solid electrolyte materials]

[0121] First, the sulfide-based inorganic solid electrolyte material of the present embodiment will be described.

[0122] The sulfide-based inorganic solid electrolyte material of the present embodiment has a particle size d when the cumulative frequency is 50% in the volume-based cumulative frequency distribution curve measured using a laser diffraction scattering particle size distribution measuring device. 50This is a sulfide-based inorganic solid electrolyte material with a thickness of 0.1 μm or more and 100 μm or less, and a sulfide-based inorganic solid electrolyte material having a bonding area of ​​10% or less as measured according to the method below.

[0123] (method)

[0124] (1) A SUS304 plate measuring 8 cm in length × 9 cm in width is installed such that the vertical side is tangent to the horizontal plane and the inclination is 45° with respect to the horizontal plane. The arithmetic mean roughness Ra measured according to JIS B 0601 (2013) is 0.017 μm or more and 0.023 μm or less, the maximum height Rz is 0.14 μm or more and 0.18 μm or less, and the ten-point average roughness Rzjis is 0.12 μm or more and 0.16 μm or less.

[0125] (2) Using a sieve with a mesh size of 250 μm, 10 g of sulfide-based inorganic solid electrolyte material is dropped onto the SUS304 plate from a height of 10 cm from the horizontal plane, so that the entire SUS304 plate is covered with the sulfide-based inorganic solid electrolyte material.

[0126] (3) One 47 g zirconia ball is dropped three times from a height of 5 cm from the top of the SUS304 plate, so that it only touches the top of the SUS304 plate and does not touch the surface of the SUS304 plate to which the sulfide-based inorganic solid electrolyte material is attached.

[0127] (4) Measure the area of ​​the surface of the SUS304 plate to which the sulfide-based inorganic solid electrolyte material is attached after impact, and calculate the ratio (attachment area) to the area of ​​one side of the SUS304 plate.

[0128] Examples of raw materials for sulfide-based inorganic solid electrolyte materials include P2S5, Li2S, and Li3N. For instance, since P2S5 is an unstable ionic crystalline powder with high reactivity, it is vitrified by processing such as mechanical milling together with Li2S, and then stabilized by crystallizing through heat treatment. The crystallinity of this stabilized sulfide-based inorganic solid electrolyte material affects the lithium ion conductivity of the solid electrolyte film obtained using the sulfide-based inorganic solid electrolyte material. At this time, if the vitrification of the sulfide-based inorganic solid electrolyte material by mechanical milling, etc., is insufficient and the desired crystalline phase is not formed during heat treatment, the lithium ion conductivity of the resulting solid electrolyte film is reduced.

[0129] In addition, sulfide-based inorganic solid electrolyte materials manufactured using conventional mechanical milling methods sometimes exhibited variations in lithium ion conductivity depending on the manufacturing batch, as insufficiently reacted sulfide-based inorganic solid electrolyte materials were mixed into the sulfide-based inorganic solid electrolyte materials recovered from the manufacturing apparatus.

[0130] According to the inventors' review, a sulfide-based inorganic solid electrolyte material is prepared such that the adhesion area of ​​the sulfide-based inorganic solid electrolyte material to a SUS304 plate is 10% or less; that is, 10 g of the sulfide-based inorganic solid electrolyte material is dropped onto a SUS304 plate installed with a 45° inclination with respect to the horizontal plane, with the vertical side being tangent to the horizontal plane, and having an arithmetic mean roughness Ra measured according to JIS B 0601 (2013) of 0.017 μm or more and 0.023 μm or less, a maximum height Rz of 0.14 μm or more and 0.18 μm or less, and a ten-point average roughness Rzjis of 0.12 μm or more and 0.16 μm or less, using a sieve with a mesh size of 250 μm from a height of 10 cm from the horizontal plane, and 47 g of zirconia balls are dropped onto the top of the SUS304 plate from the top of the SUS304 plate. By appropriately selecting manufacturing conditions and formulations so that the adhesion area when dropped from a height of 5 cm and subjected to three impacts is within a specific range, it is possible to stably obtain a sulfide-based inorganic solid electrolyte material having high lithium ion conductivity while maintaining conventional handling properties and lithium ion conductivity, and reducing the variation in lithium ion conductivity per manufacturing batch, thereby arriving at the present invention.

[0131] Although the reason is not certain, the fact that the adhesion area to the SUS304 plate is small can be rephrased as meaning that there is less unreacted raw material composition that is unstable and highly reactive. As a result, it is believed that a sulfide-based inorganic solid electrolyte material can be provided that exhibits low variation in lithium ion conductivity between manufacturing batches while maintaining conventional handling properties and lithium ion conductivity.

[0132] Here, the sulfide-based inorganic solid electrolyte material of the present embodiment has an upper limit value of the adhesion area measured according to the above (method) of 10% or less, more preferably 8% or less, and even more preferably 5% or less. Because the adhesion area is less than the above upper limit value, the unreacted raw material composition in the sulfide-based inorganic solid electrolyte material can be reduced.

[0133] In addition, the lower limit of the attachment area is not specifically limited, but, for example, is 0% or more.

[0134] In order to make the sulfide-based inorganic solid electrolyte of the present embodiment have the aforementioned attachment surface area,

[0135] (i) Raw material mixing ratio of sulfide-based inorganic solid electrolyte materials

[0136] (ii) Manufacturing method

[0137] It is desirable to appropriately select the above two points. Here, (i) as the raw material mixing ratio, it is desirable to set the molar ratio of the content of Li to the content of P (Li / P) and the molar ratio of the content of S to the content of P (S / P) among the sulfide-based inorganic solid electrolyte materials described below to be within the range described below.

[0138] In addition, (ii) as a manufacturing method, it is preferable to use a device in which the inner wall surface is a smooth surface with low surface roughness. An example of such a device in which the inner wall surface is a smooth surface is the device (10) described later.

[0139] The sulfide-based inorganic solid electrolyte material of the present embodiment has a particle size d when the cumulative frequency is 50% in the volume-based cumulative frequency distribution curve measured using a laser diffraction scattering particle size distribution measuring device. 50This is 0.1 μm or more, preferably 1 μm or more, more preferably 2 μm or more, even more preferably 3 μm or more, even more preferably 5 μm or more, even more preferably 10 μm or more, even more preferably 15 μm or more, even more preferably 20 μm or more, even more preferably 30 μm or more, even more preferably 40 μm or more, even more preferably 50 μm or more, even more preferably 60 μm or more, and even more preferably 70 μm or more. Particle diameter d of the sulfide-based inorganic solid electrolyte material 50 By making it greater than the lower limit value mentioned above, the lithium ion conductivity of the obtained solid electrolyte membrane can be further improved.

[0140] In addition, the particle size d 50 This is 100 μm or less, preferably 95 μm or less, more preferably 90 μm or less, even more preferably 85 μm or less, even more preferably 80 μm or less, and even more preferably 75 μm or less. Particle size d of the sulfide-based inorganic solid electrolyte material 50 By keeping it below the upper limit value mentioned above, good handling performance can be maintained.

[0141] The sulfide-based inorganic solid electrolyte material of the present embodiment is preferably a powdered sulfide-based inorganic solid electrolyte material comprising Li, P, and S as constituent elements.

[0142] In the sulfide-based inorganic solid electrolyte material of the present embodiment, from the perspective of further improving lithium ion conductivity, electrochemical stability, stability in moisture and air, and handling properties, the molar ratio of the content of Li to the content of P in the sulfide-based inorganic solid electrolyte material (Li / P) is preferably 1.0 or more and 10.0 or less, more preferably 1.5 or more and 5.0 or less, even more preferably 1.8 or more and 4.5 or less, even more preferably 2.0 or more and 4.4 or less, even more preferably 2.3 or more and 4.3 or less, even more preferably 2.8 or more and 3.8 or less, even more preferably 3.0 or more and 3.5 or less, even more preferably 3.2 or more and 3.4 or less, and even more preferably 3.3.

[0143] In addition, the molar ratio of the content of S to the content of P (S / P) is preferably 1.0 or more and 10.0 or less, more preferably 2.5 or more and 6.0 or less, even more preferably 3.0 or more and 5.0 or less, even more preferably 3.5 or more and 4.8 or less, even more preferably 3.7 or more and 4.5 or less, even more preferably 3.9 or more and 4.1 or less, and even more preferably 4.0.

[0144] Here, the content of Li, P, and S in the solid electrolyte material of the present embodiment can be determined, for example, by ICP emission spectroscopy.

[0145] In the sulfide-based inorganic solid electrolyte material of the present embodiment, the lower limit of the lithium ion conductivity of the sulfide-based inorganic solid electrolyte material by the AC impedance method under measurement conditions of 27.0°C, an applied voltage of 10 mV, and a measurement frequency range of 0.1 Hz to 7 MHz is preferably 1.0 × 10⁻⁶. －4 S·cm －1 Ideally, 2.2×10 －4 S·cm －1 Ideally, 2.5×10 －4 S·cm －1Ideally, 2.8×10 －4 S·cm －1 That is all, and more preferably 3.0×10 －4 S·cm －1 That is all, and more preferably 5.0×10 －4 S·cm －1 This is the ideal, and more preferably 7.0×10 －4 S·cm －1 That is all, and more preferably 1.0×10 －3 S·cm －1 This is the ideal, and more preferably 1.2×10 －3 S·cm －1 That is all, and more preferably 1.5×10 －3 S·cm －1 That is all.

[0146] If the lithium ion conductivity of the sulfide-based inorganic solid electrolyte material of the present embodiment is greater than or equal to the lower limit value, an all-solid-state lithium-ion battery with even better battery characteristics can be obtained.

[0147] In addition, the upper limit of the lithium ion conductivity of sulfide-based inorganic solid electrolyte materials is not specifically limited, but, for example, 3.0 × 10⁻⁶ －3 S·cm －1 It is as follows.

[0148] As for the shape of the sulfide-based inorganic solid electrolyte material of the present embodiment, for example, a particulate form can be used.

[0149] The sulfide-based inorganic solid electrolyte material of the present embodiment is used, for example, in a solid electrolyte layer constituting an all-solid-state lithium-ion battery.

[0150] Examples of all-solid-state lithium-ion batteries applying the sulfide-based inorganic solid electrolyte material of the present embodiment include a positive electrode layer, a solid electrolyte layer, and a negative electrode layer stacked in this order. In this case, the solid electrolyte layer is composed of a sulfide-based inorganic solid electrolyte material.

[0151] [Method for manufacturing sulfide-based inorganic solid electrolyte materials]

[0152] Next, a method for manufacturing the sulfide-based inorganic solid electrolyte material of the present embodiment will be described.

[0153] The method for manufacturing the sulfide-based inorganic solid electrolyte material of the present embodiment is different from the conventional method for manufacturing sulfide-based inorganic solid electrolyte materials. For the sulfide-based inorganic solid electrolyte material of the present embodiment, in which the attachment area on the SUS304 plate is within the above range, it is important to highly control manufacturing conditions such as the composition ratio of the sulfide-based inorganic solid electrolyte material and vitrifying the inorganic composition used as a raw material.

[0154] More specifically, the sulfide-based inorganic solid electrolyte material of the present embodiment can be obtained by a manufacturing method comprising the processes of (A) and (B) below. In addition, the manufacturing method of the sulfide-based inorganic solid electrolyte material of the present embodiment may additionally include the process of (C) below.

[0155] Process (A): A process for preparing an inorganic composition comprising two or more inorganic compounds that are raw materials.

[0156] Process (B): A process of obtaining a sulfide-based inorganic solid electrolyte material by mechanically treating an inorganic composition to chemically react the raw inorganic compounds with each other while vitrifying the inorganic composition.

[0157] Process (C): A process of crushing, classifying, or granulating the obtained sulfide-based inorganic solid electrolyte material.

[0158] Each process is explained in detail below.

[0159] (Process of preparing an inorganic composition (A))

[0160] First, an inorganic composition containing two or more inorganic compounds as raw materials is prepared.

[0161] As inorganic compounds, two or more compounds are used that chemically react with each other by mechanical treatment to produce a sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements. These inorganic compounds can be appropriately selected depending on the sulfide-based inorganic solid electrolyte material to be produced, and for example, lithium sulfide, phosphorus sulfide, lithium nitride, etc. can be used.

[0162] The above inorganic composition can be obtained, for example, by mixing two or more inorganic compounds as raw materials in a predetermined molar ratio so that the sulfide-based inorganic solid electrolyte material produced becomes the desired composition ratio.

[0163] As for the method of mixing two or more inorganic compounds, there are no particular limitations as long as the mixing method can uniformly mix each inorganic compound, but for example, mixing can be done using a mortar and pestle, ball mill, bead mill, vibratory mill, impact grinder, mixer (pug mixer, ribbon mixer, tumbler mixer, drum mixer, V-type mixer, etc.), airflow grinder, etc.

[0164] When mixing each inorganic compound, mixing conditions such as stirring speed, processing time, temperature, reaction pressure, and gravitational acceleration applied to the mixture can be appropriately determined according to the throughput of the mixture.

[0165] The lithium sulfide used as a raw material is not particularly limited; commercially available lithium sulfide may be used, for example, lithium sulfide obtained by the reaction of lithium hydroxide with hydrogen sulfide may be used. From the perspective of obtaining high-purity sulfide-based inorganic solid electrolyte materials and suppressing side reactions, it is desirable to use lithium sulfide with low impurity content.

[0166] Here, in the present embodiment, lithium sulfide also includes lithium polysulfide.

[0167] The phosphorus sulfide used as a raw material is not particularly limited, and commercially available phosphorus sulfide (e.g., P2S5, P4S3, P4S7, P4S5, etc.) can be used. From the perspective of obtaining high-purity sulfide-based inorganic solid electrolyte materials and suppressing side reactions, it is desirable to use phosphorus sulfide with low impurity content. In addition, instead of phosphorus sulfide, it is also possible to use elemental phosphorus (P) and elemental sulfur (S) in equivalent molar ratios. As long as elemental phosphorus (P) and elemental sulfur (S) are industrially produced and sold, they can be used without any particular limitations.

[0168] Lithium nitride may be used as the raw material inorganic compound. Here, since the nitrogen in lithium nitride is discharged into the system as N2, by using lithium nitride as the raw material inorganic compound, it becomes possible to increase only the Li composition in sulfide-based inorganic solid electrolyte materials containing Li, P, and S as constituent elements.

[0169] The lithium nitride of the present embodiment is not particularly limited; commercially available lithium nitride (e.g., Li3N, etc.) may be used, or, for example, lithium nitride obtained by the reaction of metallic lithium (e.g., Li foil) with nitrogen gas may be used. From the perspective of obtaining a high-purity solid electrolyte material and suppressing side reactions, it is preferable to use lithium nitride with low impurity content.

[0170] (Process of vitrifying the inorganic composition (B))

[0171] Subsequently, by mechanically treating the inorganic composition to chemically react the raw inorganic compounds with each other, the inorganic composition is vitrified to obtain a sulfide-based inorganic solid electrolyte material.

[0172] Here, mechanical treatment is capable of vitrifying an inorganic composition by causing a chemical reaction through mechanical collision of two or more inorganic compounds that are raw materials, such as mechanochemical treatment.

[0173] Here, mechanochemical treatment is a method of vitrifying a mixture by applying mechanical energy, such as shear force, impact force, or centrifugal force, to the mixture. Devices for performing vitrification by mechanochemical treatment include crushers and dispersers such as ball mills, bead mills, vibratory mills, turbomills, mechanofusions, disc mills, and roll mills, as well as impact crushers consisting of a mechanism combining rotation, extrusion, and impact, such as rock cutters, vibratory drills, and impact drivers. Among these, as an impact crusher consisting of a mechanism combining rotation, extrusion, and impact, it is preferable to use the device (10) described below in order to solve the problem of this application.

[0174] In addition, it is preferable to perform the mechanochemical treatment under an inert atmosphere. This allows for the suppression of reactions between the inorganic composition and water vapor, oxygen, etc.

[0175] In addition, an inert atmosphere refers to a vacuum atmosphere or an inert gas atmosphere. In the above inert atmosphere, it is preferable that the dew point be -50°C or lower to avoid contact with moisture, and more preferable that it be -60°C or lower. The above inert gas atmosphere refers to an atmosphere of inert gases such as argon gas, helium gas, and nitrogen gas. To prevent the incorporation of impurities into the product, it is preferable that these inert gases be of high purity. As for the method of introducing inert gas into the mixing system, there are no particular limitations as long as the mixing system is filled with an inert gas atmosphere, but methods such as purging the inert gas or continuously introducing a certain amount of inert gas may be cited.

[0176] In addition, when vitrifying the inorganic composition, an aprotic organic solvent such as hexane, toluene, or xylene may be added to vitrify the composition in a state where each raw material is dispersed in the solvent.

[0177] Mixing conditions, such as rotational speed, processing time, temperature, reaction pressure, and gravitational acceleration applied to the inorganic composition, when vitrifying the inorganic composition can be appropriately determined according to the type of inorganic composition and the throughput. Generally, the faster the rotational speed, the faster the rate of glass formation, and the longer the processing time, the higher the conversion rate to glass.

[0178] Typically, when X-ray diffraction analysis is performed using CuKα rays as a source, if the diffraction peak of the inorganic composition disappears or decreases, it can be determined that the inorganic composition has vitrified and the desired sulfide-based inorganic solid electrolyte material is obtained.

[0179] (Device (10))

[0180] Here, an apparatus (10) preferably used for manufacturing the sulfide-based inorganic solid electrolyte material of the present embodiment will be described using drawings.

[0181] FIG. 1 is a drawing showing an apparatus (10) for manufacturing a sulfide-based inorganic solid electrolyte material according to the present embodiment. FIG. 2 is a top view of the rotary table (212) and a plurality of balls (214) of the grinding unit (200) shown in FIG. 1. FIG. 3 is a cross-sectional view A-A´ of FIG. 2. The apparatus (10) manufactures a sulfide-based inorganic solid electrolyte material from a plurality of types of inorganic compounds (A1). In FIG. 1, the upward direction in FIG. 1 is the upward direction in the vertical direction, and the downward direction in FIG. 1 is the downward direction in the vertical direction. In FIG. 2, the pressing unit (216) is not shown for illustrative purposes. In FIG. 3, the black arrow indicates the flow of a plurality of types of inorganic compounds (A1). In FIG. 3, the white arrow indicates the flow of an inert gas.

[0182] An overview of the device (10) is described using FIG. 1. The device (10) is equipped with a blower unit (100), a crusher unit (200), a first recovery unit (300), and a system (S). The blower unit (100) sends inert gas. The crusher unit (200) repeatedly vitrifies a plurality of types of inorganic compounds (A1) by mechanical energy and blows up the vitrified plurality of types of inorganic compounds (A1) by the inert gas sent from the blower unit (100). At least a portion of the plurality of types of inorganic compounds (A1) blown up by the inert gas enters the first recovery unit (300). The first recovery unit (300) returns the said at least portion of the plurality of types of inorganic compounds (A1) toward the crusher unit (200). The system (S) (e.g., the pipe (Pa), buffer tank (110), pipe (Pb), pipe (Pc) and pipe (Pi) described below) circulates an inert gas from the blower unit (100) through the crusher unit (200) and the first recovery unit (300) to the blower unit (100).

[0183] At this time, by making the inner wall surface of the device of the grinding section (200) a smooth surface with a small arithmetic mean roughness Ra, it is possible to obtain a sulfide-based inorganic solid electrolyte material with an attachment area of ​​10% or less obtained by the above-described (method).

[0184] Although the reason is not certain, it is thought that by making the inner wall surface of the grinding section (200) a smooth surface with a small arithmetic mean roughness Ra, the attachment and deposition of unreacted raw material composition and sulfide-based inorganic solid electrolyte material to the inner wall surface of the device is prevented, making it easier to feed unreacted raw material composition and sulfide-based inorganic solid electrolyte material into the grinding section (200). As a result, it is thought that mechanochemical treatment of unreacted raw material composition and sulfide-based inorganic solid electrolyte material proceeds more easily, thereby preventing the raw material composition from being recovered unreacted. Furthermore, it is thought that it is possible to make the device capable of producing sulfide-based inorganic solid electrolyte material that improves the recovery yield during manufacturing and enables the homogenization of physical properties of the product.

[0185] Specifically, it is preferable that the upper limit of the arithmetic mean roughness Ra measured according to JIS B 0601 (2013) of the inner wall surface of the grinding section (200) is 0.02 μm, more preferable that it is 0.015 μm, more preferable that it is 0.01 μm, and particularly preferable that it is 0.005 μm.

[0186] In addition, the lower limit of the arithmetic mean roughness Ra of the inner wall surface of the device of the grinding section (200) is not specifically limited, but, for example, is 0 μm or more, 0.001 μm or more, and 0.003 μm or more.

[0187] Conventional anti-adhesion technologies include blast treatment, which creates fine irregularities on the surface, but it is known that no anti-adhesion effect is obtained for the raw material mixture of sulfide-based inorganic solid electrolyte materials. Although the reason is not certain, it is thought that P2S5, a raw material of sulfide-based inorganic solid electrolyte materials, is an unstable ionic crystal powder with high reactivity and has a high chemical affinity with the metal plate used on the inner wall surface of the device. It is thought that the presence of fine irregularities on the surface of the metal plate used on the inner wall surface of the device increases the surface area of ​​the inner wall surface, resulting in the raw material mixture of sulfide-based inorganic solid electrolyte materials being strongly adhered to and deposited on the inner wall surface of the device.

[0188] Meanwhile, in the device of the present embodiment, by making the surface of the metal plate used on the inner wall of the device into a smooth surface with small fine irregularities, the surface area of ​​the inner wall of the device is reduced, making it difficult for the chemical reaction between the raw material mixture of the sulfide-based inorganic solid electrolyte material and the metal plate to proceed. As a result, it is believed that the adhesion and deposition of the raw material mixture of the sulfide-based inorganic solid electrolyte material to the inner wall of the device can be prevented.

[0189] In order to reduce the arithmetic mean roughness Ra of the inner wall surface of the device as described above, this is achieved by performing a known polishing treatment on the surface of the metal plate used on the inner wall surface of the device. An example of a known polishing treatment is buff polishing.

[0190] In addition, in the device (10), it is preferable that the upper limit of the maximum height Rz measured according to JIS B 0601 (2013) of the inner wall surface of the grinding section (200) is 0.16 μm, more preferable that it is 0.13 μm, more preferable that it is 0.10 μm, and particularly preferable that it is 0.05 μm. By making the maximum height Rz of the inner wall surface of the grinding section (200) less than or equal to the upper limit, it is possible to more effectively prevent the attachment and deposition of the raw material mixture of the sulfide-based inorganic solid electrolyte material on the inner wall surface of the device, thereby improving the recovery yield during manufacturing and further reducing the variation in lithium ion conductivity of the obtained sulfide-based inorganic solid electrolyte material for each manufacturing batch.

[0191] In addition, the lower limit value of the maximum height Rz of the inner wall surface of the device of the grinding section (200) is not specifically limited, but, for example, is 0 μm or more, 0.01 μm or more, and 0.03 μm or more.

[0192] In addition, in the device (10), the upper limit of the ten-point average roughness Rzjis measured according to JIS B 0601 (2013) of the inner wall surface of the grinding section (200) is preferably 0.14 μm, more preferably 0.10 μm, more preferably 0.07 μm, and particularly preferably 0.04 μm. By making the ten-point average roughness Rzjis of the inner wall surface of the grinding section (200) less than or equal to the upper limit, the attachment and deposition of the raw material mixture of the sulfide-based inorganic solid electrolyte material on the inner wall surface of the device can be more effectively prevented, thereby improving the recovery yield during manufacturing and further reducing the variation in lithium ion conductivity of the obtained sulfide-based inorganic solid electrolyte material for each manufacturing batch.

[0193] In addition, the lower limit of the ten-point average roughness Rzjis of the inner wall surface of the device of the grinding section (200) is not specifically limited, but, for example, is 0 μm or more, 0.01 μm or more, and 0.03 μm or more.

[0194] Using Figure 1 below, the structure of the device (10) will be explained in more detail.

[0195] The device (10) comprises a blower unit (100), a buffer tank (110), a crushing unit (200), a first recovery unit (300), a first receiving unit (310), a second recovery unit (400), a second receiving unit (410), a pressure reducing unit (500), a pipe (Pa), a plurality of pipes (Pb) (5th pipe), a pipe (Pc) (2nd pipe), a pipe (Pd) (6th pipe), a pipe (Pe) (1st pipe), a pipe (Pf) (3rd pipe), a pipe (Pg), a pipe (Ph) (4th pipe), a pipe (Pi), a pipe (Pj), a pipe (Pk), a pipe (Pl), a pipe (Pm), a pipe (Pn), a pipe (Po), a valve (Va1), a plurality of valves (Vb1) (5th valve), a valve (Vc1), a valve (Vc2) (2nd valve), a valve (Vc3), a valve (Vd1) (6th valve), a valve (Ve1) (1st valve), and a valve (Ve2). It is equipped with valve (Vf1) (third valve), valve (Vg1), valve (Vh1), valve (Vh2), valve (Vi1), valve (Vi2), valve (Vj1), valve (Vk1), valve (Vl1), valve (Vm1), valve (Vn1), valve (Vo1), line (Le) (first line), line (Lh) (second line), and exhaust duct (D).

[0196] The pipe (Pa) is connected to the gas outlet (104) of the blower unit (100) and the gas inlet (112) of the buffer tank (110). A valve (Va1) is installed in the pipe (Pa).

[0197] Each of the plurality of pipes (Pb) is connected to each of the plurality of gas outlets (114) of the buffer tank (110) and each of the plurality of gas inlets (202) of the crushing unit (200). Each of the plurality of valves (Vb1) is installed in each of the plurality of pipes (Pb). In one example, when viewed from above the rotary table (212) of the crushing unit (200) (details will be described later), the plurality of pipes (Pb) are arranged around the rotary table (212), and specifically, are arranged rotationally symmetrically with respect to the center of the rotary table (212) (rotation axis (R) described later).

[0198] The pipe (Pc) is connected to the material discharge pipe (206) of the crushing unit (200) and the suction port (302) of the first recovery unit (300). Valves (Vc1), (Vc2), and (Vc3) are installed in the pipe (Pc) and are arranged in the order of valves (Vc1), (Vc2), and (Vc3) from the material discharge pipe (206) of the crushing unit (200) to the suction port (302) of the first recovery unit (300).

[0199] The pipe (Pd) is connected to the material supply pipe (204) of the crushing section (200) and the material discharge port (304) of the first recovery section (300). A valve (Vd1) is installed in the pipe (Pd).

[0200] The pipe (Pe) is connected to the material supply port (308) of the first receiving section (310) and the first recovery section (300). Valves (Ve1) and (Ve2) are installed in the pipe (Pe) and are arranged in the order of valves (Ve1) and (Ve2) from the first receiving section (310) to the material supply port (308) of the first recovery section (300). Additionally, valve (Ve1) is detachably mounted to the pipe (Pe) together with the first receiving section (310). In other words, when valve (Ve1) is removed from the pipe (Pe), the first receiving section (310) and valve (Ve1) can be integrated. Furthermore, the pipe (Pe) is connected to a line (Le) between valves (Ve1) and valve (Ve2). The interior of the pipe (Pe) can be replaced with a vacuum or inert gas through the line (Le). That is, the line (Le) can depressurize the interior of the pipe (Pe) and at the same time introduce an inert gas into the pipe (Pe).

[0201] The pipe (Pf) is connected to the part of the pipe (Pc) located between valve (Vc1) and valve (Vc2) (i.e., between the crushing section (200) and valve (Vc2)) and to the suction port (402) of the second recovery section (400). Valve (Vf1) is installed in the pipe (Pf).

[0202] Pipe (Pg) is connected to the portion of pipe (Pc) located between valve (Vc2) and valve (Vc3) and to the gas discharge pipe (406) of the second recovery unit (400). Valve (Vg1) is installed in pipe (Pg).

[0203] The pipe (Ph) is connected to the material discharge port (404) of the second receiving section (410) and the second recovery section (400). Valves (Vh1) and (Vh2) are installed in the pipe (Ph) and are arranged in the order of valves (Vh1) and (Vh2) from the second receiving section (410) to the material discharge port (404) of the second recovery section (400). Additionally, the pipe (Ph) is connected to a line (Lh) between valves (Vh1) and (Vh2). The interior of the pipe (Ph) can be replaced with a vacuum or an inert gas through the line (Lh). That is, the line (Lh) can depressurize the interior of the pipe (Ph) while simultaneously introducing an inert gas into the pipe (Ph).

[0204] Piping (Pi) is connected to the gas outlet (306) of the first recovery unit (300) and the gas inlet (102) of the blower unit (100). Valves (Vi1) and (Vi2) are installed in piping (Pi) and are arranged in the order of valves (Vi1) and (Vi2) from the gas outlet (306) of the first recovery unit (300) to the gas inlet (102) of the blower unit (100).

[0205] Pipe (Pj) is connected to the portion of pipe (Pi) located between the gas outlet (306) of the first recovery section (300) and the valve (Vi1), and to the portion of pipe (Pi) located between the gas inlet (102) of the blower section (100) and the valve (Vi2). The valve (Vj1) is installed in pipe (Pj).

[0206] The pipe (Pk) is connected to the adjustment port (116) of the buffer tank (110) and the exhaust duct (D). A valve (Vk1) is installed in the pipe (Pk).

[0207] The pipe (Pl) is connected to the gas outlet (208) of the crushing section (200) and the pressure reducing section (500). A valve (Vl1) is installed in the pipe (Pl).

[0208] The pipe (Pm) is connected to the pressure reducing section (500) and the exhaust duct (D). The valve (Vm1) is installed in the pipe (Pm).

[0209] The pipe (Pn) is connected to the part of the pipe (Pl) located between the gas outlet (208) of the crushing section (200) and the valve (Vl1), and to the exhaust duct (D). The valve (Vn1) is installed in the pipe (Pn).

[0210] Pipe (Po) branches off from pipe (Pi) and leads to the exhaust duct (D). Specifically, pipe (Pi) has a portion that connects to the end of pipe (Pj) located between the valve (Vi2) and the gas inlet (102) of the blower unit (100). Pipe (Po) is connected to the exhaust duct (D) through the portion of pipe (Pi) located between the portion of pipe (Pi) and the gas inlet (102) of the blower unit (100). The valve (Vo1) is installed in pipe (Po).

[0211] The blower unit (100) draws gas from the gas inlet (102) of the blower unit (100) into the pipe (Pj). Additionally, the blower unit (100) discharges the gas drawn in from the gas inlet (102) of the blower unit (100) through the gas outlet (104) of the blower unit (100). In this way, the blower unit (100) sends gas to the buffer tank (110) via the pipe (Pa). Furthermore, the rotational speed of the motor of the blower unit (100) can be changed by the inverter (106), and the flow rate of the gas sent from the blower unit (100) can be arbitrarily changed according to the rotational speed of the motor.

[0212] Gas sent from the blower unit (100) via pipe (Pa) enters the gas inlet (112) of the buffer tank (110). The gas that enters the buffer tank (110) passes through a plurality of gas outlets (114) of the buffer tank (110) and is sent to the crushing unit (200) via a plurality of pipes (Pb). The pressure of the gas inside the buffer tank (110) is controlled by a valve (Vk1).

[0213] Gas sent from a buffer tank (110) via a plurality of pipes (Pb) enters the plurality of gas inlets (202) of the crushing unit (200). Material sent from a first receiving unit (310) via pipe (Pe), a first recovery unit (300), and pipe (Pd) enters the material supply pipe (204) of the crushing unit (200). At least a portion of the material and at least a portion of the gas inside the crushing unit (200) are discharged from the material discharge pipe (206) of the crushing unit (200). The pressure inside the crushing unit (200) can be reduced by a pressure reduction unit (500). Additionally, the gas inside the crushing unit (200) can be discharged to an exhaust duct (D) via pipe (Pn).

[0214] The first recovery unit (300) sucks in materials and gas within the pipe (Pc) from the suction port (302) of the first recovery unit (300). Additionally, the first recovery unit (300) discharges the materials sucked in from the suction port (302) of the first recovery unit (300) from the material discharge port (304) of the first recovery unit (300). In this way, the first recovery unit (300) sends materials to the crushing unit (200) via the pipe (Pd). Additionally, the first recovery unit (300) discharges the gas sucked in from the suction port (302) of the first recovery unit (300) from the gas discharge port (306) of the first recovery unit (300). In this way, the first recovery unit (300) sends gas to the blower unit (100) via the pipe (Pi). The first recovery unit (300) is, for example, a dust collector.

[0215] The second recovery unit (400) sucks up materials and gas within pipes (Pc) and pipes (Pf) from the suction port (402) of the second recovery unit (400). Additionally, the second recovery unit (400) discharges the materials sucked up from the suction port (402) of the second recovery unit (400) from the material discharge port (404) of the second recovery unit (400). In this way, the second recovery unit (400) sends materials to the second receiving unit (410) via pipe (Ph). Additionally, the second recovery unit (400) discharges the gas sucked up from the suction port (402) of the second recovery unit (400) from the gas discharge pipe (406) of the second recovery unit (400). The second recovery unit (400) is, for example, a cyclone dust collector.

[0216] Here, in the device (10) of the present embodiment, it is preferable to make the inner wall surface of the device, which is the part through which the powder can pass, a smooth surface with a small arithmetic mean roughness. By adopting the above configuration, it is possible to further reduce the variation in lithium ion conductivity for each manufacturing batch of the sulfide-based inorganic solid electrolyte material obtained. In addition, the part through which the powder can pass may include, for example, a first recovery section, a second recovery section, a first receiving section, a second receiving section, a first pipe, a second pipe, a third pipe, a fourth pipe, a fifth pipe, and a sixth pipe.

[0217] Specifically, it is preferable that the upper limit of the arithmetic mean roughness Ra measured according to JIS B 0601 (2013) on the inner wall surface of the device in one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe is 0.02 μm, more preferable that it is 0.015 μm, more preferable that it is 0.01 μm, and particularly preferable that it is 0.005 μm. By making the arithmetic mean roughness Ra lower than or equal to the upper limit, it is possible to more effectively prevent the attachment and deposition of the raw material mixture of the sulfide-based inorganic solid electrolyte material on the inner wall surface of the device, thereby improving the recovery yield during manufacturing and further reducing the variation in lithium ion conductivity of the obtained sulfide-based inorganic solid electrolyte material for each manufacturing batch.

[0218] In addition, the lower limit of the arithmetic mean roughness Ra is not specifically limited, but, for example, is 0 μm or more, 0.001 μm or more, and 0.003 μm or more.

[0219] In the device (10) of the present embodiment, it is preferable that the upper limit of the maximum height Rz measured according to JIS B 0601 (2013) on the inner wall surface of the device in one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe is 0.16 μm, more preferable that it is 0.13 μm, more preferable that it is 0.10 μm, and particularly preferable that it is 0.05 μm. By making the maximum height Rz less than or equal to the upper limit, the attachment and deposition of the raw material mixture of the sulfide-based inorganic solid electrolyte material on the inner wall surface of the device can be more effectively prevented, thereby improving the recovery yield during manufacturing and further reducing the variation in lithium ion conductivity of the obtained sulfide-based inorganic solid electrolyte material for each manufacturing batch.

[0220] In addition, the lower limit of the maximum height Rz is not specifically limited, but, for example, is 0 μm or more, 0.01 μm or more, and 0.03 μm or more.

[0221] In the device (10) of the present embodiment, the upper limit of the ten-point average roughness Rzjis measured according to JIS B 0601 (2013) on the inner wall surface of the device in one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe is preferably 0.14 μm, more preferably 0.10 μm, more preferably 0.07 μm, and particularly preferably 0.04 μm. By making the ten-point average roughness Rzjis lower than the upper limit, the attachment and deposition of the raw material mixture of the sulfide-based inorganic solid electrolyte material on the inner wall surface of the device can be more effectively prevented, thereby improving the recovery yield during manufacturing and further reducing the variation in lithium ion conductivity of the obtained sulfide-based inorganic solid electrolyte material for each manufacturing batch.

[0222] In addition, the lower limit of the above ten-point average roughness Rzjis is not specifically limited, but, for example, is 0 μm or more, 0.01 μm or more, and 0.03 μm or more.

[0223] Next, the structure of the crushing unit (200) will be explained using FIGS. 2 and FIGS. 3.

[0224] The grinding unit (200) has a rotating table (212), a plurality of balls (214), and a pressing unit (216). In the example shown in FIG. 2, the number of the plurality of balls (214) is seven. However, the number of the plurality of balls (214) is not limited to the example shown in FIG. 2.

[0225] The rotating table (212) is rotatable around a rotation axis (R). The rotation axis (R) of the rotating table (212) passes through the center of the rotating table (212) along the height direction (thickness direction) of the rotating table (212). The height direction (thickness direction) of the rotating table (212) follows the vertical direction. A plurality of balls (214) are arranged around the rotation axis (R) of the rotating table (212), specifically, arranged rotationally symmetrically with respect to the rotation axis (R). The plurality of balls (214) rotate together with the rotation of the rotating table (212). Additionally, each of the plurality of balls (214) is rotatable with respect to the rotation axis (R1) that rotates together with the rotation of the rotating table (212). The rotation axis (R1) of each ball (214) passes through the center of the ball (214) along the height direction (thickness direction) of the ball (214). The height direction (thickness direction) of the ball (214) follows the vertical direction. The pressing part (216) presses a plurality of balls (214) toward the rotating table (212) from the opposite side of the rotating table (212).

[0226] Next, using FIGS. 1 to 4, an example of a method for manufacturing a sulfide-based inorganic solid electrolyte material from a plurality of inorganic compounds (A1) by means of an apparatus (10) will be described.

[0227] The valves (Ve1) and (Ve2) are closed, and a plurality of inorganic compounds (A1) are received in the first receiving section (310). Specifically, first, the first receiving section (310) is removed from the pipe (Pe) together with the valve (Ve1). Then, a plurality of inorganic compounds (A1) are received in the first receiving section (310). The reception of the plurality of inorganic compounds (A1) is carried out in an atmosphere controlled by an inert gas (e.g., inside a glove box). Then, the first receiving section (310) and the valve (Ve1) are mounted on the pipe (Pe) with the valve (Ve1) closed. In this case, even if the first receiving section (310) and the valve (Ve1) are exposed to the atmosphere, the plurality of inorganic compounds (A1) in the first receiving section (310) can be prevented from being exposed to the atmosphere (air) because the valve (Ve1) is closed. Additionally, when the first receiving section (310) is installed, the air that enters the pipe (Pe) can be replaced with an inert gas in the line (Le) connected to the pipe (Pe). This prevents the inorganic compound (A1) from being exposed to the atmosphere (air) when it passes through the pipe (Pe). Subsequently, valves (Ve1), (Ve2), and (Vd1) are opened, and multiple types of inorganic compounds (A1) are sent from the first receiving section (310) to the crushing section (200) via the pipe (Pe), the first recovery section (300), and the pipe (Pd). That is, the first receiving section (310) receives multiple types of inorganic compounds (A1) supplied to the crushing section (200).

[0228] Additionally, valves (Ve1), (Ve2), (Vf1), (Vg1), (Vh1), (Vh2), (Vj1), (Vl1), (Vm1), (Vn1) and (Vo1) are closed, and valves (Va1), (Vb1), (Vc1), (Vc2), (Vc3), (Vd1), (Vi1) and (Vi2) are opened to supply inert gas to the part of the piping (Pi) located between valves (Vi1) and (Vi2). Subsequently, the blower unit (100) is operated while controlling the pressure inside the buffer tank (110) by valve (Vk1). Thus, the system (S), that is, the system extending from the blower unit (100) to the blower unit (100) via the pipe (Pa), buffer tank (110), pipe (Pb), crusher unit (200), pipe (Pc), first recovery unit (300), and pipe (Pi), circulates inert gas and is also closed from the outside (i.e., the system (S) is not exposed to the atmosphere (air).).

[0229] The supply of inert gas to the portion of the pipe (Pi) located between valve (Vi1) and valve (Vi2) may be performed before or after supplying multiple types of inorganic compounds (A1) from the first receiving portion (310) to the crushing portion (200), or while supplying multiple types of inorganic compounds (A1) from the first receiving portion (310) to the crushing portion (200). Additionally, the location where the inert gas is supplied does not have to be the portion of the pipe (Pi) located between valve (Vi1) and valve (Vi2), but may be any part of the system (S). Furthermore, the inert gas may be supplied to multiple parts of the system (S) (including the portion of the pipe (Pi) located between valve (Vi1) and valve (Vi2)).

[0230] The inert gas introduced into the device (10) is, for example, nitrogen gas. The nitrogen gas is supplied, for example, from a nitrogen cylinder via a nitrogen purification device. In this example, the impurity concentration of the nitrogen gas (for example, moisture concentration or oxygen concentration) can be lowered. For example, the moisture concentration of the nitrogen gas can be 400 ppm or less, preferably 40 ppm or less, more preferably 2 ppm or less, and the oxygen concentration of the nitrogen gas can be 400 ppm or less, preferably 40 ppm or less, more preferably 2 ppm or less. However, the inert gas may be a gas different from the nitrogen gas, for example, argon gas.

[0231] Additionally, the grinding unit (200) is operated. Specifically, the rotary table (212) is rotated around the rotation axis (R), and each ball (214) is rotated around the rotation axis (R1), and the plurality of balls (214) are pressed toward the rotary table (212) by the pressing unit (216). The operation of the grinding unit (200) may be initiated before or after supplying a plurality of types of inorganic compounds (A1) from the first receiving unit (310) to the grinding unit (200), or it may be initiated while supplying a plurality of types of inorganic compounds (A1) from the first receiving unit (310) to the grinding unit (200). The grinding unit (200) repeats the process of vitrifying a plurality of types of inorganic compounds (A1) by mechanical energy and blowing up the vitrified plurality of types of inorganic compounds (A1) by an inert gas sent from the blower unit (100) as follows.

[0232] First, as indicated by the black arrow extending from the material supply pipe (204) toward the rotary table (212) in FIG. 3, a plurality of inorganic compounds (A1) supplied from the first receiving portion (310) pass through the material supply pipe (204) and reach the center or periphery of the rotary table (212) (rotation axis (R) and periphery thereof).

[0233] After that, as indicated by the two black arrows extending toward both sides from the periphery of the center (rotation axis (R)) of the rotating table (212) in FIG. 3, a plurality of inorganic compounds (A1) move from the center (rotation axis (R)) of the rotating table (212) toward the ball (214) by the centrifugal force generated by the rotation of the rotating table (212), and enter the gap between the rotating table (212) and the ball (214). The plurality of inorganic compounds (A1) that have entered the gap between the rotating table (212) and the ball (214) are vitrified by mechanical energy. Specifically, shear stress and compressive stress are applied to the plurality of inorganic compounds (A1) that have entered the gap between the rotating table (212) and the ball (214) by the rotation of the ball (214) and the pressing of the ball (214) toward the rotating table (212) by the pressing part (216). Due to the shear stress and compressive stress, multiple types of inorganic compounds (A1) are vitrified. That is, mechanical milling is performed on multiple types of inorganic compounds (A1).

[0234] As indicated by the two white arrows located on both sides of the rotary table (212), the plurality of balls (214), and the pressing part (216) in FIG. 3, a flow of inert gas is generated from the bottom to the top of the grinding part (200) on the outside of the rotary table (212). This flow is generated by inert gas sent from the blower part (100) through the gas inlet (202) of the grinding part (200). As indicated by the two black arrows located on both sides of the plurality of balls (214) and the pressing part (216) in FIG. 3, vitrified multiple types of inorganic compounds (A1) are blown up by the inert gas. At this time, the rotational speed of the motor of the blower unit (100) is kept low by the inverter (106), thereby keeping the flow rate of the inert gas sent from the blower unit (100) to the crushing unit (200) low so that it does not exit from the material discharge pipe (206) as long as it can become an inorganic compound (A1).

[0235] As indicated by two black arrows extending from the outer side of the rotary table (212) toward the center of the rotary table (212) on the pressing part (216) in FIG. 3, a portion of the inorganic compounds (A1) that are blown up by an inert gas moves from the outer side of the rotary table (212) toward the center of the rotary table (212) on the upper side of the pressing part (216). This inorganic compound (A1) reaches the center of the rotary table (212) or its periphery (rotation axis (R) and its periphery) in the same way as the inorganic compound (A1) supplied from the material supply pipe (204). After that, mechanical milling is performed on the inorganic compound (A1) in the same way as described above.

[0236] As indicated by the two black arrows extending upward toward the upper part of the pressing part (216) in FIG. 3, other parts of the multiple types of inorganic compounds (A1) that are blown up by the inert gas may enter the material discharge pipe (206) without returning to the rotating table (212). For example, multiple types of inorganic compounds (A1) with small particle sizes are likely to enter the material discharge pipe (206) without returning to the rotating table (212). The multiple types of inorganic compounds (A1) that enter the material discharge pipe (206) are sent to the first recovery part (300) via the pipe (Pc), and from the first recovery part (300) are sent to the material supply pipe (204) of the crushing part (200) via the pipe (Pd) and return to the rotating table (212). Therefore, even if multiple types of inorganic compounds (A1) enter the material discharge pipe (206), mechanical milling can be performed again by the grinding unit (200).

[0237] While mechanical milling of the grinding unit (200) is being performed, as described above, the system (S), that is, the system extending from the blower unit (100) through the pipe (Pa), buffer tank (110), pipe (Pb), grinding unit (200), pipe (Pc), first recovery unit (300), and pipe (Pi) to the blower unit (100), circulates an inert gas and is also closed from the outside. Thus, contact between multiple types of inorganic compounds (A1) and air can be reduced.

[0238] By performing mechanical milling on a plurality of inorganic compounds (A1) by the grinding unit (200), the plurality of inorganic compounds (A1) are vitrified, and a sulfide-based inorganic solid electrolyte material is manufactured from the plurality of inorganic compounds (A1).

[0239] Figure 4 is a drawing showing a variation of Figure 3.

[0240] The crushing section (200) additionally has a cover section (220). The cover section (220) is located above the pressing section (216). As indicated by the white arrow extending along the cover section (220) in FIG. 4, the cover section (220) directs the flow of inert gas that sprays up a plurality of types of inorganic compounds (A1) toward the center of the crushing section (200) (the rotation axis (R) of the rotating table (212)) and toward the bottom of the crushing section (200). In this case, compared to the case where the cover section (220) is not installed, the amount of a plurality of types of inorganic compounds (A1) that are sprayed up by the inert gas and enter the material discharge pipe (206) can be reduced, and the amount of a plurality of types of inorganic compounds (A1) that are sprayed up by the inert gas and return to the rotating table (212) can be increased. Therefore, compared to the case where the cover part (220) is not installed, the efficiency of mechanical milling of the grinding part (200) can be improved.

[0241] Next, an example of a method for taking a sulfide-based inorganic solid electrolyte material out of the device (10) is described.

[0242] By closing valve (Vc2) and opening valves (Vf1) and (Vg1), and by controlling the inverter (106) connected to the motor of the blower unit (100) to increase the rotational speed of the motor of the blower unit (100), the flow rate of the inert gas sent to the gas inlet (202) of the crushing unit (200) is increased (at this stage, valves (Vh1) and (Vh2) are closed). As the flow rate of the inert gas sent to the gas inlet (202) of the crushing unit (200) increases, the sulfide-based inorganic solid electrolyte material blown up by the inert gas within the crushing unit (200) is sent into the material discharge pipe (206) without rotating the rotating table (212) with little or no return. The sulfide-based inorganic solid electrolyte material sent into the material discharge pipe (206) enters the suction port (402) of the second recovery unit (400) via pipes (Pc) and (Pf). Thereby, the sulfide-based inorganic solid electrolyte material is recovered by the second recovery unit (400). Next, valves (Vh1) and (Vh2) are opened. Thereby, the sulfide-based inorganic solid electrolyte material recovered by the second recovery unit (400) enters the second receiving unit (410) via pipe (Ph). Next, valves (Vh1) and (Vh2) are closed. Next, the second receiving unit (410) is detached from pipe (Ph). In this case, since valves (Vh1) and (Vh2) are closed, the inside of pipe (Ph) can be prevented from being exposed to the atmosphere (air). When the second receiving section (410) is installed in the pipe (Ph) again, the air that has entered the pipe (Ph) can be replaced with an inert gas in the line (Lh) connected to the pipe (Ph). This prevents the sulfide-based inorganic solid electrolyte material from being exposed to the atmosphere (air) when it passes through the pipe (Ph).

[0243] Next, an example of the operation of the pressure reduction unit (500) is described.

[0244] The interior of the grinding unit (200) may be exposed to the atmosphere (gas) by cleaning, for example, internal parts of the grinding unit (200) (e.g., rotary table (212), ball (214), or pressing unit (216)). In this case, the air inside the grinding unit (200) can be removed by reducing the pressure inside the grinding unit (200) by the pressure reduction unit (500). For example, the pressure reduction unit (500) can be operated by closing a plurality of valves (Vb1), valve (Vc1), valve (Vd1), and valve (Vn1), and opening valve (Vl1) and valve (Vm1).

[0245] The sulfide-based inorganic solid electrolyte material produced using the device (10) of the present embodiment can be recovered without adhering to the inner wall surface of the device. Because of this, the amount of unreacted raw material composition in the sulfide-based inorganic solid electrolyte material can be reduced, and consequently, a sulfide-based inorganic solid electrolyte material with excellent stability and a small variation in lithium ion conductivity per production batch can be produced.

[0246] In addition, the apparatus (10) of the present embodiment can be used to produce not only sulfide-based inorganic solid electrolyte materials like the present embodiment, but also other known inorganic materials. Examples of known inorganic materials include oxide-based inorganic solid electrolyte materials, other lithium-based inorganic solid electrolyte materials, positive active materials and negative active materials described later.

[0247] As oxide-based inorganic solid electrolyte materials, for example, NASICON type such as LiTi2(PO4)3, LiZr2(PO4)3, LiGe2(PO4)3, (La 0.5＋x Li 0.5－3x Examples include perovskite types such as TiO3, Li2O-P2O5 materials, Li2O-P2O5-Li3N materials, etc.

[0248] Other lithium-based inorganic solid electrolyte materials include, for example, LiPON, LiNbO3, LiTaO3, Li3PO4, and LiPO4. 4－xN x Examples include (where x is 0 < x ≤ 1), LiN, LiI, LISICON, etc. In addition, glass ceramics obtained by precipitating crystals of these inorganic solid electrolytes can also be used as inorganic solid electrolyte materials.

[0249] (Process of grinding, classifying, or aggregating (C))

[0250] In the method for manufacturing a sulfide-based inorganic solid electrolyte material according to the present embodiment, additional processes of crushing, classifying, or granulating the obtained sulfide-based inorganic solid electrolyte material may be performed as needed. For example, by finely grinding the material and then adjusting the particle size through classification and granulation operations, a sulfide-based inorganic solid electrolyte material having a desired particle size can be obtained. The crushing method is not particularly limited, and known crushing methods such as mixers, air-flow grinding, mortars, rotary mills, and coffee mills may be used. Furthermore, the classification method is not particularly limited, and known methods such as sieves may be used.

[0251] It is preferable to perform these grinding or classifications under an inert gas atmosphere or a vacuum atmosphere to prevent contact with moisture in the air.

[0252] [Solid Electrolyte Membrane]

[0253] Next, the solid electrolyte membrane of the present embodiment will be described.

[0254] The solid electrolyte membrane of the present embodiment is a solid electrolyte membrane comprising the sulfide-based inorganic solid electrolyte material of the present embodiment described above as a main component.

[0255] The solid electrolyte membrane of the present embodiment is used, for example, in a solid electrolyte layer constituting an all-solid-state lithium-ion battery.

[0256] Examples of all-solid-state lithium-ion batteries applying the solid electrolyte membrane of the present embodiment include a positive electrode layer, a solid electrolyte layer, and a negative electrode layer stacked in this order. In this case, the solid electrolyte layer is composed of a solid electrolyte membrane.

[0257] The average thickness of the solid electrolyte film of the present embodiment is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 200 μm or less, and even more preferably 20 μm or more and 100 μm or less. If the average thickness of the solid electrolyte film is greater than or equal to the lower limit value, the defect of the sulfide-based inorganic solid electrolyte material and the occurrence of cracks on the surface of the solid electrolyte film can be further suppressed. In addition, if the average thickness of the solid electrolyte film is less than or equal to the upper limit value, the impedance of the solid electrolyte film can be further reduced. As a result, the battery characteristics of the all-solid-state lithium-ion battery obtained can be further improved.

[0258] The solid electrolyte membrane of the present embodiment is preferably a pressure-molded body of a powdered sulfide-based inorganic solid electrolyte material. That is, it is preferable to pressurize a particulate inorganic solid electrolyte material to form a solid electrolyte membrane having a certain strength through the anchoring effect between the inorganic solid electrolyte materials.

[0259] By forming a pressure-molded body, bonding occurs between the inorganic solid electrolyte materials, and the strength of the resulting solid electrolyte film is further increased. As a result, defects in the inorganic solid electrolyte materials and the occurrence of cracks on the surface of the inorganic solid electrolyte materials can be further suppressed.

[0260] The content of the sulfide-based inorganic solid electrolyte material of the present embodiment in the solid electrolyte membrane of the present embodiment is preferably 98 mass% or more, more preferably 99 mass% or more, and even more preferably 100 mass% when the total of the solid electrolyte membrane is 100 mass%. By doing so, the contact between inorganic solid electrolyte materials is improved, and the interfacial contact resistance of the solid electrolyte membrane can be reduced. As a result, the lithium ion conductivity of the solid electrolyte membrane can be further improved. Furthermore, by using such a solid electrolyte membrane with excellent lithium ion conductivity, the battery characteristics of the all-solid-state lithium-ion battery obtained can be further improved.

[0261] The planar shape of the solid electrolyte membrane is not particularly limited and can be appropriately selected to match the shapes of the electrode layer and the current collector layer, but for example, it can be rectangular.

[0262] In addition, the solid electrolyte membrane of the present embodiment may include a binder resin, but the content of the binder resin is preferably less than 0.5 mass%, more preferably 0.1 mass% or less, even more preferably 0.05 mass% or less, and even more preferably 0.01 mass% or less when the total of the solid electrolyte membrane is 100 mass%. Furthermore, it is even more preferable that the solid electrolyte membrane of the present embodiment substantially does not include a binder resin, and most preferable that it does not include a binder resin.

[0263] As a result, the contact between solid electrolyte materials is improved, which can lower the interfacial contact resistance of the solid electrolyte membrane. Consequently, the lithium ion conductivity of the solid electrolyte membrane can be further enhanced. Furthermore, by using a solid electrolyte membrane with such excellent lithium ion conductivity, the battery characteristics of an all-solid-state lithium-ion battery can be improved.

[0264] In addition, "substantially not containing binder resin" means that it may be contained to an extent that the effect of the present embodiment is not impaired, and the content may be, for example, 0.005 mass% or 0.001 mass%. In addition, when an adhesive resin layer is installed between the solid electrolyte layer and the anode layer or the cathode layer, the adhesive resin originating from the adhesive resin layer present near the interface between the solid electrolyte layer and the adhesive resin layer is excluded from the "binder resin in the solid electrolyte film."

[0265] The above binder resin refers to a binder commonly used in lithium-ion batteries to bind solid electrolyte materials together, and examples include polyvinyl alcohol, polyacrylic acid, carboxymethylcellulose, polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, polyimide, etc.

[0266] The solid electrolyte membrane of the present embodiment can be obtained, for example, by depositing a powdered sulfide-based inorganic solid electrolyte material in a film shape on the surface of a mold cavity or on the surface of a substrate, and then applying pressure to the sulfide-based inorganic solid electrolyte material deposited in a film shape.

[0267] The method of pressurizing the above sulfide-based inorganic solid electrolyte material is not particularly limited, and for example, when the powdered sulfide-based inorganic solid electrolyte material is deposited on the cavity surface of a mold, a press using a mold and a presser can be used; when the powdered sulfide-based inorganic solid electrolyte material is deposited on the surface of a substrate, a press using a mold and a presser, a roll press, a flat plate press, etc., can be used.

[0268] The pressure applied to the sulfide-based inorganic solid electrolyte material is, for example, 10 MPa or more and 500 MPa or less.

[0269] In addition, if necessary, the sulfide-based inorganic solid electrolyte material deposited in a film shape may be heated while simultaneously being pressurized. When heating and pressurizing are performed, fusion and bonding occur between the sulfide-based inorganic solid electrolyte materials, and the strength of the resulting solid electrolyte film is further increased. As a result, the defects of the sulfide-based inorganic solid electrolyte material and the occurrence of cracks on the surface of the sulfide-based inorganic solid electrolyte material can be further suppressed.

[0270] The heating temperature of the sulfide-based inorganic solid electrolyte material is, for example, 40°C or higher and 500°C or lower.

[0271] [All-solid-state lithium-ion battery]

[0272] Next, the all-solid-state lithium-ion battery (600) of the present embodiment will be described. FIG. 5 is a schematic cross-sectional view showing an example of the structure of the all-solid-state lithium-ion battery (600) of the present invention. The all-solid-state lithium-ion battery (600) of the present embodiment is a lithium-ion secondary battery, but it may also be a lithium-ion primary battery.

[0273] The all-solid-state lithium-ion battery (600) of the present embodiment is formed by stacking a positive electrode layer (610), a solid electrolyte layer (620), and a negative electrode layer (630) in this order. Additionally, the solid electrolyte layer (620) is composed of the solid electrolyte membrane of the present embodiment.

[0274] In addition, the all-solid-state lithium-ion battery (600) of the embodiment can also be made into a bipolar lithium-ion battery by stacking two or more unit cells composed of a positive electrode layer (610), a solid electrolyte layer (620), and a negative electrode layer (630).

[0275] The shape of the all-solid-state lithium-ion battery (600) is not particularly limited and may include cylindrical, coin-shaped, prismatic, film-shaped, or any other shape.

[0276] The all-solid-state lithium-ion battery (600) of the present embodiment is manufactured in accordance with a generally known method. For example, it is manufactured by stacking a positive electrode layer (610), a solid electrolyte layer (620), and a negative electrode layer (630) and forming them into a cylindrical, coin-shaped, prismatic, film-shaped, or any other shape.

[0277] The positive electrode layer (610) is not particularly limited and can use a positive electrode generally used in all-solid-state lithium-ion batteries. The positive electrode layer (610) is not particularly limited but can be manufactured according to generally known methods. For example, it can be obtained by forming a positive electrode active material layer containing a positive electrode active material on a current collector such as aluminum foil.

[0278] The thickness and density of the positive active material layer are determined appropriately according to the intended use of the battery, and are not particularly limited, and can be set based on generally known information.

[0279] The above positive active material layer includes a positive active material.

[0280] The cathode active material is not particularly limited, and any generally known cathode active material usable in the cathode layer of an all-solid-state lithium-ion battery may be used. For example, lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese oxide (LiMn2O4), solid solution oxide (Li2MnO3-LiMO2(M=Co, Ni, etc.)), lithium-manganese-nickel oxide (LiNi 1／3 Mn 1／3 Co 1／3Composite oxides such as O2), olivine-type lithium phosphate (LiFePO4); conductive polymers such as polyaniline and polypyrrole; sulfide-based cathode active materials such as Li2S, CuS, Li-Cu-S compounds, TiS2, FeS, MoS2, Li-Mo-S compounds, Li-Ti-S compounds, and Li-V-S compounds; materials in which sulfur is used as an active material, such as sulfur-impregnated acetylene black, sulfur-impregnated porous carbon, and a mixture of sulfur and carbon; etc. These cathode active materials may be used as a single type or in combination of two or more types.

[0281] Among these, a sulfide-based cathode active material is preferred in terms of having a higher discharge capacity density and also having better cycle characteristics, and one or more selected from Li-Mo-S compounds, Li-Ti-S compounds, and Li-V-S compounds are more preferred.

[0282] Here, the Li-Mo-S compound contains Li, Mo, and S as constituent elements and can typically be obtained by mixing and grinding the raw materials, molybdenum sulfide and lithium sulfide, through mechanochemical treatment or the like.

[0283] In addition, Li-Ti-S compounds contain Li, Ti, and S as constituent elements and can typically be obtained by mixing and grinding raw materials, such as titanium sulfide and lithium sulfide, through mechanochemical treatment.

[0284] Li-V-S compounds contain Li, V, and S as constituent elements and can usually be obtained by mixing and grinding vanadium sulfide and lithium sulfide, which are raw materials, through mechanochemical treatment.

[0285] The above positive active material layer is not particularly limited, but may include one or more materials selected from solid electrolyte materials, binders, conductive aids, etc. as components other than the positive active material.

[0286] The mixing ratio of various materials in the positive active material layer is not particularly limited as it is determined appropriately according to the intended use of the battery, and can be set based on generally known information.

[0287] The negative electrode layer (630) is not particularly limited and can be any that is generally used in all-solid-state lithium-ion batteries. The negative electrode layer (630) is not particularly limited but can be manufactured according to generally known methods. For example, it can be obtained by forming a negative electrode active material layer containing a negative electrode active material on a current collector such as copper foil.

[0288] The thickness and density of the negative electrode active material layer are determined appropriately according to the intended use of the battery, and are not particularly limited, and can be set based on generally known information.

[0289] The above cathode active material layer includes a cathode active material.

[0290] As for the negative electrode active material, there are no particular limitations, and generally known negative electrode active materials usable in the negative electrode layer of an all-solid-state lithium-ion battery may be used. For example, carbonaceous materials such as natural graphite, artificial graphite, resin carbon, carbon fiber, activated carbon, hard carbon, and soft carbon; metallic materials mainly composed of tin, tin alloy, silicon, silicon alloy, gallium, gallium alloy, indium, indium alloy, aluminum, and aluminum alloy; conductive polymers such as polyacene, polyacetylene, and polypyrrole; metallic lithium; and lithium titanium composite oxide (e.g., Li4Ti5O). 12 Examples include ) etc. These cathode active materials may be used as a single type or in combination of two or more types.

[0291] The above-mentioned negative electrode active material layer is not particularly limited, but may include one or more materials selected from, for example, solid electrolyte materials, binders, and conductive aids as components other than the negative electrode active material.

[0292] The mixing ratio of various materials in the negative electrode active material layer is not particularly limited as it is determined appropriately according to the intended use of the battery, and can be set based on generally known information.

[0293] Although embodiments of the present invention have been described above with reference to the drawings, these are examples of the present invention, and various configurations other than those described above may also be adopted.

[0294] Examples

[0295] The present invention is described below by way of examples and comparative examples, but the present invention is not limited thereto.

[0296] First, the adhesion of the raw material mixture to the inner wall surface of the device was evaluated using test specimens of Examples A to C and Comparative Examples A to G.

[0297] [1] Mixture of raw materials for sulfide-based inorganic solid electrolyte materials

[0298] Li2S (manufactured by Furukawa Kikai Kinzoku Co., Ltd., purity 99.9%), P2S5 (manufactured by Kanto Kagaku Co., Ltd.), and Li3N (manufactured by Furukawa Kikai Kinzoku Co., Ltd.) were used as raw materials, respectively.

[0299] These powders were mixed in a molar ratio of 71.0:23.7:5.3 to form a raw material mixture of a sulfide-based inorganic solid electrolyte material.

[0300] [2] Test piece

[0301] If good results regarding the adhesion and deposition of the raw material mixture are obtained in a plate made of the same material as the inner wall surface of the device, it is believed that the same results will be obtained within the device of this embodiment. Accordingly, a test specimen simulating the inner wall surface of the device was fabricated using SUS304, the same material used for the inner wall surface of the device. The method of fabricating the test specimen is shown below.

[0302] <Example A>

[0303] A test specimen made of SUS304 (W: 100 mm × D: 100 mm × H: 2 mm) was buffed using #800 abrasive and designated as test specimen 1. After buffing, the arithmetic mean roughness Ra of the surface of test specimen 1, measured according to JIS B 0601 (2013), was 0.005 μm, the maximum height Rz was 0.030 μm, and the ten-point average roughness Rzjis was 0.026 μm.

[0304] <Example B>

[0305] A test specimen made of SUS304 (W: 100 mm × D: 100 mm × H: 2 mm) was buffed using #800 abrasive and designated as test specimen 2. After buffing, the arithmetic mean roughness Ra of the surface of test specimen 2, measured according to JIS B 0601 (2013), was 0.010 μm, the maximum height Rz was 0.065 μm, and the ten-point average roughness Rzjis was 0.058 μm.

[0306] <Example C>

[0307] A test specimen (W: 100 mm × D: 100 mm × H: 2 mm) made of SUS304 was buffed using #800 abrasive and was designated as test specimen 3. The arithmetic mean roughness Ra of the surface of test specimen 3 after buffing, measured according to JIS B 0601 (2013), was 0.020 μm, the maximum height Rz was 0.160 μm, and the ten-point average roughness Rzjis was 0.140 μm.

[0308] <Comparative Example A>

[0309] Buff polishing was performed on a test specimen (W: 100 mm × D: 100 mm × H: 2 mm) made of SUS304 using #800 abrasive. After buff polishing, blast treatment was performed under conditions of average shot particle size: 2 μm, blast pressure: 0.5 MPa, blast distance: 300 mm, and blast angle: 90°, and the result was test specimen 4. The arithmetic mean roughness Ra of the surface of test specimen 4 after blast treatment, measured according to JIS B 0601 (2013), was 3.0 μm, the maximum height Rz was 18.8 μm, and the ten-point average roughness Rzjis was 17.0 μm.

[0310] <Comparative Example B>

[0311] Buff polishing was performed on a test specimen (W: 100 mm × D: 100 mm × H: 2 mm) made of SUS304 using #800 abrasive. After buff polishing, blast treatment was performed under conditions of average shot particle size: 1 μm, blast pressure: 0.5 MPa, blast distance: 300 mm, and blast angle: 90°, and the specimen was designated as test specimen 5. The arithmetic mean roughness Ra of the surface of test specimen 5 after blast treatment, measured according to JIS B 0601 (2013), was 1.5 μm, the maximum height Rz was 7.0 μm, and the ten-point average roughness Rzjis was 6.1 μm.

[0312] <Comparative Example C>

[0313] Buff polishing was performed on a test specimen (W: 100 mm × D: 100 mm × H: 2 mm) made of SUS304 using #800 abrasive. After buff polishing, blast treatment was performed under conditions of average shot particle size: 0.8 μm, blast pressure: 0.5 MPa, blast distance: 300 mm, and blast angle: 90°, and the specimen was prepared as test specimen 6. The arithmetic mean roughness Ra of the surface of test specimen 6 after blast treatment, measured according to JIS B 0601 (2013), was 1.0 μm, the maximum height Rz was 5.7 μm, and the ten-point average roughness Rzjis was 4.6 μm.

[0314] <Comparative Example D>

[0315] Buff polishing was performed on a test specimen (W: 100 mm × D: 100 mm × H: 2 mm) made of SUS304 using #800 abrasive. After buff polishing, blast treatment was performed under conditions of average shot particle size: 0.3 μm, blast pressure: 0.5 MPa, blast distance: 300 mm, and blast angle: 90°, and the specimen was designated as test specimen 7. The arithmetic mean roughness Ra of the surface of test specimen 7 after blast treatment, measured according to JIS B 0601 (2013), was 0.5 μm, the maximum height Rz was 2.4 μm, and the ten-point average roughness Rzjis was 2.1 μm.

[0316] <Comparative Example E>

[0317] Buff polishing was performed on a test specimen (W: 100 mm × D: 100 mm × H: 2 mm) made of SUS304 using #800 abrasive. After buff polishing, blast treatment was performed under conditions of average shot particle size: 0.2 μm, blast pressure: 0.5 MPa, blast distance: 300 mm, and blast angle: 90°, and the specimen was prepared as test specimen 8. The arithmetic mean roughness Ra of the surface of test specimen 8 after blast treatment, measured according to JIS B 0601 (2013), was 0.3 μm, the maximum height Rz was 1.6 μm, and the ten-point average roughness Rzjis was 1.2 μm.

[0318] <Comparative Example F>

[0319] Buff polishing was performed on a test specimen (W: 100 mm × D: 100 mm × H: 2 mm) made of SUS304 using #800 abrasive. After buff polishing, blast treatment was performed under conditions of average shot particle size: 0.05 μm, blast pressure: 0.5 MPa, blast distance: 300 mm, and blast angle: 90°, and the specimen was designated as test specimen 9. The arithmetic mean roughness Ra of the surface of test specimen 9 after blast treatment, measured according to JIS B 0601 (2013), was 0.1 μm, the maximum height Rz was 0.6 μm, and the ten-point average roughness Rzjis was 0.5 μm.

[0320] <Comparative Example G>

[0321] Buff polishing was performed on a test specimen (W: 100 mm × D: 100 mm × H: 2 mm) made of SUS304 using #800 abrasive. After buff polishing, blast treatment was performed under conditions of average shot particle size: 0.01 μm, blast pressure: 0.5 MPa, blast distance: 300 mm, and blast angle: 90°, and the result was test specimen 10. The arithmetic mean roughness Ra of the surface of test specimen 10 after blast treatment, measured according to JIS B 0601 (2013), was 0.05 μm, the maximum height Rz was 0.29 μm, and the ten-point average roughness Rzjis was 0.24 μm.

[0322] [3] Constitution test

[0323] In the apparatus of the present embodiment, for example, in the piping and each receiving section, it is assumed that a large amount of sulfide-based inorganic solid electrolyte material and its raw material mixture are continuously in contact with the inner wall surface of the apparatus. Accordingly, in Examples A to C and Comparative Examples A to G, a sieving test was performed to evaluate the adhesion and deposition status of the raw material mixture on the test specimen when the raw material mixture of the sulfide-based inorganic solid electrolyte material was sieved onto the test specimen simulating the inner wall surface of the apparatus. Below, FIG. 6 shows a schematic diagram of the sieving of the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material, and FIG. 7 shows a schematic diagram of impacting with a zirconia ball (780). With reference to FIG. 6 and FIG. 7, the measurement method of the sieving test performed on the test specimen will be explained.

[0324] First, the test specimens (710) prepared in Examples A to C and Comparative Examples A to G were placed on a jig installed on a horizontal plane (720). At this time, the angle of the test specimen (710) relative to the horizontal plane (720) was adjusted to 45°. Next, 10 g of the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material was sieved and dropped using a sieve (750) with a mesh size of 250 μm at a position where the height (760) from the horizontal plane (720) was 10 cm, so that the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material covered the entire test specimen (710). In addition, at a position where the height (770) from the top of the test specimen (710) is 5 cm, a 47 g zirconia ball (780) (manufactured by Nikkato, spherical shape with a diameter of 2.5 cm) was dropped three times so as to only touch the top of the test specimen (710) and not to touch the surface of the test specimen (710) to which the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material is attached, thereby impacting the test specimen (710). Finally, the surface of the test specimen (710) after impact, to which the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material is attached, is photographed with a camera, and the photograph is separated into a powder-attached area and an unattached area using image processing software Paint.net (v4.2.16), and the area of ​​the powder-attached area is measured using image analysis software ImageJ (1.52a), and the ratio (attached area) to the area of ​​one side of the test specimen (710) is calculated, and the attached area is evaluated in the following three stages.

[0325] a: The attachment area of ​​the sulfide-based inorganic solid electrolyte material relative to the surface area of ​​the test specimen to which the sulfide-based inorganic solid electrolyte material is attached is 10% or less.

[0326] b: The area of ​​attachment of the sulfide-based inorganic solid electrolyte material relative to the area of ​​the surface of the test specimen to which the sulfide-based inorganic solid electrolyte material is attached is 30% or less.

[0327] c: The area of ​​attachment of the sulfide-based inorganic solid electrolyte material relative to the area of ​​the surface of the test specimen to which the sulfide-based inorganic solid electrolyte material is attached is 50% or less.

[0328] [4] Press test

[0329] In the apparatus of the present embodiment, for example, in the grinding section, since the ball is pressed against the rotating table by the pressing section, it is assumed that a certain amount of force is applied when the raw material mixture of the sulfide-based inorganic solid electrolyte material is pressed against the inner wall surface of the grinding section or when the raw material mixture collides with the inner wall surface of the apparatus. Accordingly, in Examples A to C and Comparative Examples A to G, a pressing test was performed to evaluate the adhesion and deposition status of the raw material mixture on the test specimen when the raw material mixture of the sulfide-based inorganic solid electrolyte material was pressed with a certain amount of force onto a test specimen simulating the inner wall surface of the apparatus. Below, FIG. 8 shows a schematic diagram of the sieving of the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material, FIG. 9 shows a schematic diagram of the pressing of the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material, FIG. 7 shows a schematic diagram of impacting the zirconia ball (780). With reference to FIG. 7 to 9, the measurement method of the pressing test performed on the test specimen will be explained.

[0330] First, the test specimen (710) prepared in Examples A to C and Comparative Examples A to G was placed on a jig installed on a horizontal plane (720). At this time, the angle of the test specimen (710) relative to the horizontal plane (720) was adjusted to 0° (parallel to the horizontal plane (720)). Then, 10 g of the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material was sieved and dropped using a sieve (750) with a mesh size of 250 μm at a position where the height (760) from the horizontal plane (720) was 10 cm, so that the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material covered the entire test specimen (710). Additionally, a patch plate (810) made by buffing a SUS304 plate with #800 abrasive was placed on top of the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material, and a weight (820) of 1 kg was placed on top of it and left for 30 seconds, thereby pressing the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material onto the test specimen (710). After leaving it, the patch plate (810) and the weight (820) were removed, and the jig was tilted from 0° to 45° over 3 seconds. Next, at a position where the height (770) from the top of the test specimen (710) is 5 cm, a 47 g zirconia ball (780) (manufactured by Nikkato, spherical shape with a diameter of 2.5 cm) was dropped three times so as to only touch the top of the test specimen (710) and not to touch the surface of the test specimen (710) to which the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material is attached, thereby impacting the test specimen (710). Finally, the surface of the test specimen (710) after impact, to which the raw material mixture (740) of the sulfide-based inorganic solid electrolyte material is attached, is photographed with a camera, and the photograph is separated into a powder-attached area and an unattached area using image processing software Paint.net (v4.2.16), and the area of ​​the powder-attached area is measured using image analysis software ImageJ (1.52a), and the ratio (attached area) to the area of ​​one side of the test specimen (710) is calculated, and the attached area is evaluated in the following three stages.

[0331] a: The attachment area of ​​the sulfide-based inorganic solid electrolyte material relative to the surface area of ​​the test specimen to which the sulfide-based inorganic solid electrolyte material is attached is 10% or less.

[0332] b: The area of ​​attachment of the sulfide-based inorganic solid electrolyte material relative to the area of ​​the surface of the test specimen to which the sulfide-based inorganic solid electrolyte material is attached is 30% or less.

[0333] c: The area of ​​attachment of the sulfide-based inorganic solid electrolyte material relative to the area of ​​the surface of the test specimen to which the sulfide-based inorganic solid electrolyte material is attached is 50% or less.

[0334]

[0335] In Examples A to C, in both the sieving and pressing tests, most of the raw material mixture detached from the test specimen after the test, which was effective in preventing the adhesion of the raw material mixture to the inner wall of the device. On the other hand, in Comparative Examples A to G, most of the raw material mixture remained on the test specimen even after the test, which could lead to adhesion to the inner wall of the device.

[0336] <Evaluation Method for Sulfide-based Inorganic Solid Electrolyte Materials>

[0337] Next, an evaluation method for the sulfide-based inorganic solid electrolyte materials obtained in Example 1 and Comparative Examples 1 to 7 below will be explained.

[0338] (1) Particle size d 50

[0339] The particle size distribution of the sulfide-based inorganic solid electrolyte materials obtained in Example 1 and Comparative Examples 1 to 7 was measured by the laser diffraction scattering method using a laser diffraction scattering particle size distribution measuring device (Malburn Co., Ltd., Mastersizer 3000). From the measurement results, for each sulfide-based inorganic solid electrolyte material, the particle size (d) at 50% accumulation in the volume-based cumulative distribution 50 , particle diameter) were calculated respectively.

[0340] (2) Attachment area

[0341] For the sulfide-based inorganic solid electrolyte materials obtained in Example 1 and Comparative Examples 1 to 7, the sieving test shown below was performed. Figure 6 below shows a schematic diagram of the sieving of the sulfide-based inorganic solid electrolyte material (740), and Figure 7 shows a schematic diagram of impacting with a zirconia ball (780). The following description is explained with reference to Figures 6 and 7.

[0342] SUS304, having an arithmetic mean roughness Ra of 0.020 μm, a maximum height Rz of 0.16 μm, and a ten-point average roughness Rzjis of 0.14 μm as measured according to JIS B 0601 (2013), was cut and processed to a length of 8 cm × width of 9 cm to form a SUS304 plate (710). After that, the SUS304 plate was installed on a table such that the installation angle (730) with respect to the horizontal plane (720) was 45°. Next, 10 g of the sulfide-based inorganic solid electrolyte material (740) obtained in Example 1 and Comparative Examples 1 to 7 was sieved and dropped using a sieve (750) with a mesh size of 250 μm at a position where the height (760) from the horizontal plane (720) was 10 cm, so that the sulfide-based inorganic solid electrolyte material (740) covered the entire SUS304 plate (710). In addition, at a position where the height (770) from the top of the SUS304 plate (710) is 5 cm, a 47 g zirconia ball (780) (manufactured by Nikkato, spherical shape with a diameter of 2.5 cm) was dropped three times so as to only touch the top of the SUS304 plate (710) and not to the surface of the SUS304 plate (710) to which the sulfide-based inorganic solid electrolyte material (740) is attached, thereby impacting the SUS304 plate (710). Finally, the surface of the SUS304 plate (710) with the sulfide-based inorganic solid electrolyte material (740) attached was photographed with a camera after the impact, and the photograph was separated into a powder-attached area and an unattached area using image processing software Paint.net (v4.2.16), and the area of ​​the powder-attached area was measured using image analysis software ImageJ (1.52a), and the ratio (attached area) to the area of ​​one side of the SUS304 plate (710) of 72 cm² was calculated.

[0343] Figure 10 shows the shape and adhesion area of ​​a SUS304 plate after a sieving test using the sulfide-based inorganic solid electrolyte materials of Example 1 and Comparative Examples 1 to 7.

[0344] (3) ICP emission spectroscopy

[0345] Using an ICP emission spectroscopic analyzer (manufactured by Seiko Instruments, SPS3000), the mass% of each element in the sulfide-based inorganic solid electrolyte materials obtained in Example 1 and Comparative Examples 1 to 7 was determined by measuring by ICP emission spectroscopic analysis, and the molar ratio of each element was calculated based on this.

[0346] (4) Measurement of lithium ion conductivity

[0347] Ten batches of the sulfide-based inorganic solid electrolyte materials of Example 1 and Comparative Examples 1 to 7 were prepared, and the lithium ion conductivity was measured by the AC impedance method for each batch.

[0348] For the measurement of lithium ion conductivity, a potentiostat / galvanostat SP-300 manufactured by Biologic was used. The sample size was φ9.5 mm and the thickness was 1.3 mm, the measurement conditions were an applied voltage of 10 mV, a measurement temperature of 27.0℃, a measurement frequency range of 0.1 Hz to 3 MHz, and the electrode was a Li foil.

[0349] Here, as a sample for measuring lithium ion conductivity, a plate-shaped sulfide-based inorganic solid electrolyte material with a thickness of 1.3 mm was used, which is obtained by annealing the powder-shaped sulfide-based inorganic solid electrolyte material obtained in Example 1 and Comparative Examples 1 to 7 at 290°C for 2 hours using a press device, and then pressing it at 270 MPa for 10 minutes.

[0350] Subsequently, the average value of 10 batches of the lithium ion conductivity of the measured sulfide-based inorganic solid electrolyte material in Example 1 and Comparative Examples 1 to 7 was calculated. This average value of 10 batches was used as the lithium ion conductivity of the sulfide-based inorganic solid electrolyte material in Example 1 and Comparative Examples 1 to 7.

[0351] (5) Evaluation of the stability of lithium ion conductivity

[0352] Ten batches of the sulfide-based inorganic solid electrolyte materials obtained in Example 1 and Comparative Examples 1 to 7 were prepared, and for each batch, the lithium ion conductivity was measured by the AC impedance method described in (4).

[0353] Next, the average value of 10 batches of measured lithium ion conductivity in Example 1 and Comparative Examples 1 to 7 was calculated. Subsequently, the stability of lithium ion conductivity among the 10 batches was evaluated in the following three steps.

[0354] A: There are no measurements less than or equal to 0.85 times the average value or greater than or equal to 1.15 times.

[0355] B: There are 1 to 2 sets of measured values ​​that are 0.85 times or less and 1.15 times or more of the average value.

[0356] C: There are 3 or more batches with measurements that are 0.85 times or less or 1.15 times or more the average value.

[0357] <Example 1>

[0358] A powdered sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements was prepared using the following procedure.

[0359] Li2S (manufactured by Furukawa Kikai Kinzoku Co., Ltd., purity 99.9%), P2S5 (manufactured by Kanto Kagaku Co., Ltd.), and Li3N (manufactured by Furukawa Kikai Kinzoku Co., Ltd.) were used as raw materials, respectively.

[0360] Next, each raw material was introduced into the device (10) (Ra: 0.005 μm, Rz: 0.030 μm, Rzjis: 0.026 μm of the inner wall surface of the device as measured according to JIS B 0601 (2013)) in such a ratio of Li2S:P2S5:Li3N = 71.0:23.7:5.3 (mol%), and mechanical milling was performed for 70 hours to obtain a sulfide-based inorganic solid electrolyte material.

[0361] Each of the obtained sulfide-based inorganic solid electrolyte materials was evaluated. The results obtained are shown in Table 2.

[0362] <Comparative Example 1>

[0363] The same raw materials as in Example 1 were used.

[0364] Next, mechanical milling was performed under the same conditions as in Example 1, except that the apparatus (10) in Example 1 was changed to a conventional apparatus (Ra: 3.0 μm, Rz: 18.8 μm, Rzjis: 17 μm of the inner wall surface of the apparatus measured according to JIS B 0601 (2013)), and a sulfide-based inorganic solid electrolyte material was obtained.

[0365] Each of the obtained sulfide-based inorganic solid electrolyte materials was evaluated. The results obtained are shown in Table 2.

[0366] <Comparative Example 2>

[0367] The same raw materials as in Example 1 were used.

[0368] Next, mechanical milling was performed under the same conditions as in Example 1, except that the apparatus (10) in Example 1 was changed to a conventional apparatus (Ra: 1.5 μm, Rz: 7.0 μm, Rzjis: 6.1 μm of the inner wall surface of the apparatus measured according to JIS B 0601 (2013)), and a sulfide-based inorganic solid electrolyte material was obtained.

[0369] Each of the obtained sulfide-based inorganic solid electrolyte materials was evaluated. The results obtained are shown in Table 2.

[0370] <Comparative Example 3>

[0371] The same raw materials as in Example 1 were used.

[0372] Next, mechanical milling was performed under the same conditions as in Example 1, except that the apparatus (10) in Example 1 was changed to a conventional apparatus (Ra: 1.0 μm, Rz: 5.7 μm, Rzjis: 4.6 μm of the inner wall surface of the apparatus measured according to JIS B 0601 (2013)), and a sulfide-based inorganic solid electrolyte material was obtained.

[0373] Each of the obtained sulfide-based inorganic solid electrolyte materials was evaluated. The results obtained are shown in Table 2.

[0374] <Comparative Example 4>

[0375] The same raw materials as in Example 1 were used.

[0376] Next, mechanical milling was performed under the same conditions as in Example 1, except that the apparatus (10) in Example 1 was changed to a conventional apparatus (Ra: 0.5 μm, Rz: 2.4 μm, Rzjis: 2.1 μm of the inner wall surface of the apparatus measured according to JIS B 0601 (2013)), and a sulfide-based inorganic solid electrolyte material was obtained.

[0377] Each of the obtained sulfide-based inorganic solid electrolyte materials was evaluated. The results obtained are shown in Table 2.

[0378] <Comparative Example 5>

[0379] The same raw materials as in Example 1 were used.

[0380] Next, mechanical milling was performed under the same conditions as in Example 1, except that the apparatus (10) in Example 1 was changed to a conventional apparatus (Ra: 0.3 μm, Rz: 1.6 μm, Rzjis: 1.2 μm of the inner wall surface of the apparatus measured according to JIS B 0601 (2013)), and a sulfide-based inorganic solid electrolyte material was obtained.

[0381] Each of the obtained sulfide-based inorganic solid electrolyte materials was evaluated. The results obtained are shown in Table 2.

[0382] <Comparative Example 6>

[0383] The same raw materials as in Example 1 were used.

[0384] Next, mechanical milling was performed under the same conditions as in Example 1, except that the apparatus (10) in Example 1 was changed to a conventional apparatus (Ra: 0.1 μm, Rz: 0.6 μm, Rzjis: 0.5 μm of the inner wall surface of the apparatus measured according to JIS B 0601 (2013)), and a sulfide-based inorganic solid electrolyte material was obtained.

[0385] Each of the obtained sulfide-based inorganic solid electrolyte materials was evaluated. The results obtained are shown in Table 2.

[0386] <Comparative Example 7>

[0387] The same raw materials as in Example 1 were used.

[0388] Next, mechanical milling was performed under the same conditions as in Example 1, except that the apparatus (10) in Example 1 was changed to a conventional apparatus (Ra: 0.05 μm, Rz: 0.29 μm, Rzjis: 0.24 μm of the inner wall surface of the apparatus measured according to JIS B 0601 (2013)), and a sulfide-based inorganic solid electrolyte material was obtained.

[0389] Each of the obtained sulfide-based inorganic solid electrolyte materials was evaluated. The results obtained are shown in Table 2.

[0390]

[0391] This application claims priority based on Japanese Patent Application No. 2021-131099 filed on August 11, 2021 and Japanese Patent Application No. 2021-131100 filed on August 11, 2021, and incorporates the entire disclosure thereof.

[0392] The present invention also includes the following aspects.

[0393] [1]

[0394] As a device for manufacturing inorganic materials,

[0395] A blower unit that sends inert gas,

[0396] A grinding unit that repeatedly vitrifies a plurality of inorganic compounds serving as the inorganic material by mechanical energy and blows up the vitrified plurality of inorganic compounds by the inert gas sent from the blower unit,

[0397] A first recovery unit into which at least a portion of the plurality of inorganic compounds blown up by the inert gas enters, and which returns the at least a portion of the plurality of inorganic compounds toward the grinding unit, and

[0398] A system for circulating the inert gas from the blower unit through the crusher unit and the first recovery unit to the blower unit.

[0399] As a device equipped with,

[0400] A device having an arithmetic mean roughness Ra of 0.02 μm or less, measured according to JIS B 0601 (2013) on the inner wall surface of the grinding section above.

[0401] [2]

[0402] In the device described in [1] above,

[0403] A device having a maximum height Rz of 0.16 μm or less, measured according to JIS B 0601 (2013) on the inner wall surface of the above-mentioned grinding section.

[0404] [3]

[0405] In the device described in [1] or [2] above,

[0406] A device having a ten-point average roughness Rzjis of the inner wall surface of the grinding section measured according to JIS B 0601 (2013) of 0.14 μm or less.

[0407] [4]

[0408] In any one of [1] to [3] above,

[0409] A first receiving portion for receiving the plurality of inorganic compounds supplied to the grinding portion,

[0410] A first pipe leading to the first recovery section and the first receiving section, and

[0411] A first valve detachably mounted to the first pipe together with the first receiving portion.

[0412] A device additionally equipped with

[0413] [5]

[0414] In the device described in [4] above,

[0415] A device further comprising a first line for introducing an inert gas into the first pipe.

[0416] [6]

[0417] In any one of claims [1] to [5] above, the device described therein

[0418] A second recovery section into which the inorganic material, blown up by the inert gas, enters

[0419] A second pipe leading to the crushing section and the first recovery section,

[0420] A second valve installed in the second pipe above,

[0421] A portion of the second pipe located between the crushing section and the second valve, and a third pipe leading to the second recovery section, and

[0422] The third valve installed in the third pipe above

[0423] A device additionally equipped with

[0424] [7]

[0425] In the device described in [6] above,

[0426] A second receiving unit for receiving the inorganic material recovered by the second recovery unit,

[0427] A fourth pipe leading to the second recovery section and the second receiving section, and

[0428] A second line introducing inert gas into the above-mentioned fourth pipe

[0429] A device additionally equipped with

[0430] [8]

[0431] In any one of [1] to [7] above,

[0432] A fifth pipe connecting the blower unit and the grinding unit,

[0433] The fifth valve installed in the above fifth pipe,

[0434] A sixth pipe for returning at least a portion of the plurality of inorganic compounds from the first recovery unit toward the grinding unit, and

[0435] The 6th valve installed in the above 6th pipe

[0436] A device additionally equipped with

[0437] [9]

[0438] In the device described in [8] above,

[0439] A device having an arithmetic mean roughness Ra of the inner wall surface of the device, measured according to JIS B 0601 (2013), of 0.02 μm or less in one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe.

[0440]

[10]

[0441] In the device described in [8] or [9] above,

[0442] A device in which the maximum height Rz measured according to JIS B 0601 (2013) of the inner wall surface of the device in one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe is 0.16 μm or less.

[0443]

[11]

[0444] In any one of the above [8] to

[10] devices,

[0445] A device having a ten-point average roughness Rzjis measured according to JIS B 0601 (2013) of the inner wall surface of one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe, which is 0.14 μm or less.

[0446]

[12]

[0447] In any one of the above [1] to

[11] devices,

[0448] A device further comprising a pressure reducing unit that reduces the internal pressure of the grinding unit.

[0449]

[13]

[0450] In any one of the above [1] to

[12] devices,

[0451] The above grinding unit is a device having a rotary table, a plurality of balls arranged around a rotation axis of the rotary table and each rotatably about a rotation axis that rotates together with the rotation of the rotary table, and a pressing unit that presses the plurality of balls toward the rotary table from the opposite side.

[0452]

[14]

[0453] In any one of the above [1] to

[13] devices,

[0454] The above-mentioned grinding section is a device having a cover section that directs the flow of the inert gas, which sprays the plurality of types of inorganic compounds, toward the center of the grinding section and the lower part of the grinding section.

[0455]

[15]

[0456] In any one of the above [1] to

[14] devices,

[0457] The above-mentioned plurality of inorganic compounds is a device containing the element Li.

[0458]

[16]

[0459] As a method for manufacturing inorganic materials,

[0460] Sending inert gas by means of a blower,

[0461] The process of vitrifying multiple types of inorganic compounds that serve as the inorganic materials by mechanical energy, and repeating the process of blowing up the vitrified multiple types of inorganic compounds by the inert gas sent from the blower unit by the grinding unit,

[0462] Returning at least a portion of the plurality of inorganic compounds that are blown up by the inert gas and enter the first recovery unit from the first recovery unit toward the grinding unit, and

[0463] Circulating the inert gas from the blower unit through the crusher unit and the first recovery unit to the blower unit.

[0464] A method including Explanation of the symbols

[0465] 10 devices 100 blower unit 102 Gas Inlet 104 Gas Outlet 106 Inverter 110 buffer tanks 112 Gas Inlet 114 Gas Outlet 116 Cho Jeong-gu 200 grinding section 202 Gas Inlet 204 Material Supply Pipe 206 Material Discharge Pipe 208 Gas exhaust outlet 212 Rotating Table 214 balls 216 Pressing part 220 cover section 300 1st Recovery Unit 302 Suction port 304 Material Discharge 306 Gas outlet 308 Material Supply Port 310 1st Reception Section 400 2nd Recovery Unit 402 Suction port 404 Material Discharge 406 Gas exhaust pipe 410 Second Reception Unit 500 pressure reduction section 600 all-solid-state lithium-ion battery 610 anode layer 620 solid electrolyte layer 630 cathode layer 710 SUS340 Plate 720 horizontal plane 730 Installation Angle 740 Sulfide-based Inorganic Solid Electrolyte Materials 750 sieves 760 Height from the horizontal plane (720) 770 Height from the top of the SUS304 plate (710) 780 Zirconia Balls 810 Patch Plate 820 Chu D exhaust duct Le 1st line Lh 2nd line Pa piping Pb Piping No. 5 PC 2nd Pipeline Pd 6th pipe Pe 1st Pipe Pf 3rd Pipe Pg piping pH 4 pipe Pi piping Pj piping Pk piping PL Piping Pm piping Pn piping Po piping S series Va1 valve Vb1 5th valve Vc1 valve Vc2 second valve Vc3 valve Vd1 6th valve Ve1 1st valve Ve2 valve Vf1 3rd valve Vg1 valve Vh1 valve Vh2 valve Vi1 valve Vi2 valve Vj1 valve Vk1 valve V1 valve Vm1 valve Vn1 valve Vo1 valve

Claims

Claim 1 Particle diameter d at a cumulative frequency of 50% in the volume-based cumulative frequency distribution curve measured using a laser diffraction scattering particle size distribution measuring device 50 A sulfide-based inorganic solid electrolyte material having a thickness of 0.1 μm or more and 100 μm or less, and a sulfide-based inorganic solid electrolyte material having a thickness of 10% or less as measured according to the following (method). (Method) (1) A SUS304 plate measuring 8 cm in length × 9 cm in width, with the arithmetic mean roughness Ra measured according to JIS B 0601 (2013) being 0.017 μm or more and 0.023 μm or less, the maximum height Rz being 0.14 μm or more and 0.18 μm or less, and the ten-point average roughness Rzjis being 0.12 μm or more and 0.16 μm or less, is installed such that the vertical side is tangent to the horizontal plane and the inclination with respect to the horizontal plane is 45°. (2) Using a sieve with a mesh size of 250 μm, 10 g of sulfide-based inorganic solid electrolyte material is dropped onto the SUS304 plate from a height of 10 cm from the horizontal plane, so that the entire SUS304 plate is covered with the sulfide-based inorganic solid electrolyte material. (3) From a height of 5 cm from the top of the SUS304 plate, 47 g of zirconia ball is dropped three times, so that it only touches the top of the SUS304 plate and does not touch the surface of the SUS304 plate to which the sulfide-based inorganic solid electrolyte material is attached. (4) After the impact, the area of ​​the surface of the SUS304 plate to which the sulfide-based inorganic solid electrolyte material is attached is measured, and the ratio (attachment area) to the area of ​​one side of the SUS304 plate is calculated. Claim 2 A sulfide-based inorganic solid electrolyte material as described in claim 1, comprising Li, P, and S as constituent elements. Claim 3 A sulfide-based inorganic solid electrolyte material as described in claim 2, wherein the molar ratio of the content of Li to the content of P (Li / P) among the sulfide-based inorganic solid electrolyte materials is 1.0 or more and 10.0 or less, and the molar ratio of the content of S to the content of P (S / P) is 1.0 or more and 10.0 or less. Claim 4 A sulfide-based inorganic solid electrolyte material as described in claim 1 or 2, wherein the lithium ion conductivity measured by the AC impedance method under measurement conditions of 27.0°C, applied voltage of 10 mV, and a measurement frequency range of 0.1 Hz to 7 MHz is 1.0 × 10⁻⁶ －4 S·cm －1 Lee Sang-in, sulfide-based inorganic solid electrolyte material. Claim 5 A solid electrolyte membrane comprising the sulfide-based inorganic solid electrolyte material described in claim 1 or 2. Claim 6 An all-solid-state lithium-ion battery comprising a positive electrode including a positive active material layer, an electrolyte layer, and a negative electrode including a negative active material layer, wherein at least one of the positive active material layer, the electrolyte layer, and the negative active material layer comprises a sulfide-based inorganic solid electrolyte material as described in claim 1 or 2. Claim 7 An apparatus for manufacturing a sulfide-based inorganic solid electrolyte material, comprising: a blower unit for sending inert gas; a grinding unit that repeatedly vitrifies a plurality of inorganic compounds that are the sulfide-based inorganic solid electrolyte material by mechanical energy and blows up the vitrified plurality of inorganic compounds by the inert gas sent from the blower unit; a first recovery unit into which at least a portion of the plurality of inorganic compounds blown up by the inert gas enters and returns the at least a portion of the plurality of inorganic compounds toward the grinding unit; and a system for circulating the inert gas from the blower unit through the grinding unit and the first recovery unit to the blower unit, wherein the arithmetic mean roughness Ra of the inner wall surface of the grinding unit, measured according to JIS B 0601 (2013), is 0.02 μm or less. Claim 8 A device described in claim 7, wherein the maximum height Rz of the inner wall surface of the grinding part of the device, measured according to JIS B 0601 (2013), is 0.16 μm or less. Claim 9 A device according to claim 7 or 8, wherein the ten-point average roughness Rzjis of the inner wall surface of the grinding part, measured according to JIS B 0601 (2013), is 0.14 μm or less. Claim 10 A device according to claim 7 or 8, further comprising a first receiving portion for receiving the plurality of inorganic compounds supplied to the grinding portion, a first pipe leading to the first recovery portion and the first receiving portion, and a first valve detachably mounted to the first pipe together with the first receiving portion. Claim 11 A device described in paragraph 10, further comprising a first line for introducing an inert gas into the first pipe. Claim 12 An apparatus described in claim 7 or 8, further comprising: a second recovery section into which the sulfide-based inorganic solid electrolyte material, which is blown up by the inert gas, enters; a second pipe leading to the crushing section and the first recovery section; a second valve installed in the second pipe; a third pipe leading to the second recovery section and a portion of the second pipe located between the crushing section and the second valve; and a third valve installed in the third pipe. Claim 13 An apparatus described in claim 12, further comprising a second receiving portion for receiving the sulfide-based inorganic solid electrolyte material recovered by the second recovery portion, a fourth pipe connecting the second recovery portion and the second receiving portion, and a second line for introducing an inert gas into the fourth pipe. Claim 14 An apparatus described in claim 7 or 8, further comprising a fifth pipe connecting the blower unit and the grinding unit, a fifth valve installed in the fifth pipe, a sixth pipe returning at least a portion of the plurality of inorganic compounds from the first recovery unit toward the grinding unit, and a sixth valve installed in the sixth pipe. Claim 15 A device described in claim 14, wherein the arithmetic mean roughness Ra measured according to JIS B 0601 (2013) of the inner wall surface of the device in one or more parts selected from the first recovery part, the second recovery part, the first receiving part, the second receiving part, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe and the sixth pipe is 0.02 μm or less. Claim 16 A device described in claim 14, wherein the maximum height Rz measured according to JIS B 0601 (2013) of the inner wall surface of the device in one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe is 0.16 μm or less. Claim 17 A device described in claim 14, wherein the ten-point average roughness Rzjis measured according to JIS B 0601 (2013) of the inner wall surface of the device in one or more parts selected from the first recovery section, the second recovery section, the first receiving section, the second receiving section, the first pipe, the second pipe, the third pipe, the fourth pipe, the fifth pipe, and the sixth pipe is 0.14 μm or less. Claim 18 A device according to claim 7 or 8, further comprising a pressure reducing unit that reduces the internal pressure of the grinding unit. Claim 19 A device according to claim 7 or 8, wherein the grinding part comprises a rotary table and a plurality of balls arranged around a rotation axis of the rotary table and each rotatably about a rotation axis that rotates together with the rotation of the rotary table, and a pressing part that presses the plurality of balls toward the rotary table from the opposite side of the rotary table. Claim 20 A device according to claim 7 or 8, wherein the grinding part has a cover part that directs the flow of the inert gas that sprays the plurality of inorganic compounds toward the center of the grinding part and toward the bottom of the grinding part. Claim 21 A device according to claim 7 or 8, wherein the plurality of inorganic compounds comprises the element Li. Claim 22 A method for manufacturing a sulfide-based inorganic solid electrolyte material by an apparatus described in claim 7, comprising: a process (A) for preparing an inorganic composition comprising two or more inorganic compounds as raw materials; and a process (B) for obtaining a sulfide-based inorganic solid electrolyte material by mechanically treating the inorganic composition to cause a chemical reaction between the inorganic compounds as raw materials and vitrifying the inorganic composition, wherein the process (B) comprises sending an inert gas by a blower, vitrifying a plurality of inorganic compounds that become the sulfide-based inorganic solid electrolyte material by mechanical energy, and repeating the process of blowing up the vitrified plurality of inorganic compounds by the inert gas sent from the blower by a grinding unit, returning at least a portion of the plurality of inorganic compounds that are blown up by the inert gas and entered into a first recovery unit from the first recovery unit toward the grinding unit, and circulating the inert gas from the blower through the grinding unit and the first recovery unit to the blower. A method for manufacturing a sulfide-based inorganic solid electrolyte material including Claim 23 A method for manufacturing a sulfide-based inorganic solid electrolyte material as described in claim 22, wherein process (C): further comprising a process of crushing, classifying, or granulating the obtained sulfide-based inorganic solid electrolyte material.

Images