JP2018101593A - Production method of solid electrolyte - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-quality solid electrolyte excellent in productivity and mass productivity.SOLUTION: There is provided a production method of a solid electrolyte for reacting a solid raw material at least in one reaction vessel. In the production method of a solid electrolyte, the reaction is a reaction using a shearing force, and powder aggregate discharged from the reaction vessel is cooled, and supplied into at least either of the reaction vessel and another reaction vessel.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a solid electrolyte.

  With the rapid spread of information-related devices such as personal computers, video cameras and mobile phones, and communication devices in recent years, development of batteries used as power sources has been regarded as important. Conventionally, an electrolyte containing a flammable organic solvent has been used as a battery for such applications. However, by using a solid battery without using a flammable organic solvent in the battery, Development of a battery in which an electrolytic solution is replaced with a solid electrolyte layer has been performed as a device capable of simplifying the device and excellent in manufacturing cost and productivity.

  As a method for producing a solid electrolyte used for a solid electrolyte layer, a method of mechanically milling raw materials using equipment such as a planetary ball mill, a ball mill, a vibration mill, etc. (for example, Patent Document 1), and industrial production and mass productivity As an excellent method, a method of reacting a raw material while pulverizing it with a hydrocarbon solvent added has been proposed (for example, Patent Document 2).

Japanese Patent Laid-Open No. 11-134937 JP 2010-140893 A

Among the methods for producing the above solid electrolyte, the method using a hydrocarbon solvent requires steps for drying and collecting the solvent, which may complicate the process. Therefore, a so-called dry method of reacting solid raw materials without using a hydrocarbon solvent has attracted attention as a simpler production method.
When reacting solid raw materials in a dry process, for example, using a device such as a ball mill as in Patent Document 1, the solid raw materials are brought into contact with each other by the action of mixing, convection, impact, shearing, etc., and the reaction proceeds. Become. The progress of the reaction between the solid raw materials is accompanied by heat generation, but if the temperature inside the reaction vessel rises due to this heat generation and the temperature cannot be adjusted, local high temperature portions and low temperature portions are generated. The solid electrolyte and by-products are produced, and in the low-temperature part, the amorphous solid electrolyte or the solid raw material in which the reaction has not progressed remains, resulting in a problem that a homogeneous solid electrolyte cannot be obtained. It will be.
In solid electrolytes, it is important to control the crystal structure, whether amorphous or crystalline, in order to develop battery performance such as conductivity. The existence of parts must be avoided as much as possible. Therefore, when the solid raw material is reacted in a dry process, more precise control of the temperature in the reaction vessel is required. The local generation of the high temperature part and the low temperature part is remarkable when a shearing force is applied to the solid raw material to cause a reaction, and it is extremely difficult to control the temperature in the reaction vessel.

  Control of the temperature in the reaction vessel is mainly performed by cooling. In this case, for example, it is conceivable to carry out slow heating by attaching a jacket such as a water cooling jacket or an air cooling jacket to the reaction vessel. However, indirect cooling methods such as jackets have limitations in controlling the temperature, especially when a solid raw material is subjected to a reaction by applying a shearing force, the temperature cannot be controlled completely, and the quality is uniform and high quality. The possibility that a solid electrolyte cannot be obtained is extremely high.

  The present invention has been made in view of such a situation, and an object thereof is to provide a high-quality solid electrolyte with excellent productivity and mass productivity.

  As a result of intensive studies to solve the above problems, the present inventors have found that the problems can be solved by the following invention.

[1] A method for producing a solid electrolyte in which a solid raw material is reacted in at least one reaction vessel, wherein the reaction is a reaction using shear force, and the powder aggregate discharged from the reaction vessel is cooled, A method for producing a solid electrolyte, comprising supplying to at least one of the reaction vessel and another reaction vessel.
[2] The method for producing a solid electrolyte according to [1], wherein the number of the reaction containers is one, the powder aggregate is cooled and supplied to the reaction container.
[3] The number of the reaction containers is two or more, the powder aggregate discharged from one reaction container is cooled, and the powder aggregate is supplied to at least one of the one reaction container and another reaction container. The method for producing a solid electrolyte according to the above [1].
[4] The method for producing a solid electrolyte according to any one of the above [1] to [3], wherein a reaction apparatus including the reaction vessel and a device that applies a shearing force to the solid raw material is used.
[5] The device according to [4], wherein the device that applies the shear force is a device including at least one selected from a single screw, a multi-screw, and a mechanism that combines a rotating blade and a rotating or fixed blade. A method for producing a solid electrolyte.
[6] The method for producing a solid electrolyte according to any one of [1] to [5], wherein a filling rate of the powder aggregate in the reaction container is 20% by volume or more.
[7] The above reactor, wherein at least one of the solid raw material and the powder aggregate supplied to the reactor has a method of extruding and discharging the powder aggregate in the reaction vessel. 4]-[6] The manufacturing method of the solid electrolyte of any one of [6].
[8] The method for producing a solid electrolyte according to any one of [1] to [7], wherein the temperature of the powder aggregate discharged from the reaction vessel is 35 ° C. or higher and 150 ° C. or lower.
[9] The production of the solid electrolyte according to [8], wherein the temperature of the powder aggregate after cooling is −100 ° C. to −5 ° C. of the temperature of the powder aggregate discharged from the reaction vessel. Method.
[10] The method for producing a solid electrolyte according to any one of [1] to [9], wherein the cooling is performed directly or indirectly using a refrigerant.
[11] The method for producing a solid electrolyte according to any one of the above [1] to [10], wherein the solid raw material contains a lithium element, a phosphorus element, and a sulfur element.
[12] The method for producing a solid electrolyte according to the above [11], wherein the solid material includes at least one of a lithium compound and a lithium metal simple substance, and at least one of a phosphorus compound and a phosphorus simple substance.
[13] The method for producing a solid electrolyte according to the above [11] or [12], wherein the solid raw material contains lithium sulfide and phosphorus sulfide.
[14] The method for producing a solid electrolyte according to any one of [11] to [13], wherein the solid raw material further contains a halogen element.
[15] The method for producing a solid electrolyte according to the above [14], wherein the halogen element is at least one of bromine and iodine.
[16] The method for producing a solid electrolyte according to the above [14] or [15], wherein the solid raw material contains at least one of lithium bromide and lithium iodide.

  According to the present invention, a high-quality solid electrolyte can be provided with excellent productivity and mass productivity.

It is a schematic diagram which shows the preferable one aspect | mode of the reaction equipment which can be used by this invention. It is a schematic diagram which shows the preferable one aspect | mode of the reaction equipment which can be used by this invention. It is a schematic diagram which shows the preferable one aspect | mode of the reaction equipment which can be used by this invention.

  Hereinafter, an embodiment of the present invention (hereinafter may be referred to as “the present embodiment”) will be described. In the present specification, the numerical values “above” and “below” relating to the description of the numerical range are numerical values that can be arbitrarily combined.

The method for producing a solid electrolyte of the present embodiment is a method for producing a solid electrolyte in which a solid raw material is reacted in at least one reaction vessel, and the reaction is a reaction using shearing force, and is discharged from the reaction vessel. Cooling the powder aggregate and supplying it to at least one of the reaction vessel and another reaction vessel.
In the present embodiment, the “powder aggregate” discharged from the reaction vessel is an unreacted solid raw material, a reactant (solid electrolyte, intermediate, byproduct), and at least one kind of powder such as impurities. It means to include. In the reaction vessel, there are at least one kind of powders such as solid raw materials, reactants (solid electrolyte, intermediates, by-products) and impurities, and the powders present in these reaction vessels. The body can also be referred to as a “powder aggregate”.

(Solid raw material)
The solid raw material used in the production method of the present embodiment can be used without particular limitation as long as it generally contains an element constituting the solid electrolyte. For example, the conductive species exhibiting ionic conductivity is at least selected from alkali metals such as lithium, sodium, potassium, rubidium, cesium and francium, and alkaline earth metals such as beryllium, magnesium, calcium, strontium, barium and radium. One element is preferable, and ion conductivity is high. Considering high battery output, alkali metals such as lithium, sodium, potassium, rubidium, cesium, and francium, and beryllium are more preferable, and lithium is particularly preferable. That is, a solid material containing at least one element selected from alkali metals such as lithium, sodium, potassium, rubidium, cesium, and francium, and alkaline earth metals such as beryllium, magnesium, calcium, strontium, barium, and radium is preferable. A solid raw material containing at least one element selected from alkali metals such as lithium, sodium, potassium, rubidium, cesium, and francium and beryllium is more preferable, and a solid raw material containing lithium element is particularly preferable.

  Moreover, what is necessary is just to select suitably according to the kind of element which comprises a desired solid electrolyte as an element contained in a solid raw material other than the element of said conductive species. Examples of the solid electrolyte include an oxide solid electrolyte, a sulfide solid electrolyte, and the like, as will be described later, and a sulfide solid electrolyte is preferable in view of increasing the output of the battery. In this case, in consideration of obtaining the above-described conductive species and the sulfide solid electrolyte, it is preferable that the solid material includes lithium element, phosphorus element, and sulfur element. By using such a solid material, a solid electrolyte containing a lithium element, a phosphorus element, and a sulfur element corresponding to the elements contained in the solid material can be obtained.

The solid material containing lithium element is at least one of lithium compounds such as lithium sulfide (Li ₂ S), lithium oxide (Li ₂ O), lithium carbonate (Li ₂ CO ₃ ), and lithium metal alone. Preferably, lithium sulfide (Li ₂ S) is particularly preferable as the lithium compound.

Examples of the solid material containing phosphorus element include phosphorus sulfide such as diphosphorus trisulfide (P ₂ S ₃ ) and diphosphorus pentasulfide (P ₂ S ₅ ), silicon sulfide (SiS ₂ ), and germanium sulfide (GeS ₂ ). Boron sulfide (B ₂ S ₃ ), gallium sulfide (Ga ₂ S ₃ ), tin sulfide (SnS or SnS ₂ ), aluminum sulfide (Al ₂ S ₃ ), zinc sulfide (ZnS), sodium phosphate (Na ₃ PO) It is preferable that it is at least 1 of phosphorus compounds, such as ₄ ), and phosphorus simple substance. As the phosphorus compound, phosphorus sulfide is preferable, and phosphorus pentasulfide (P ₂ S ₅ ) is more preferable. Phosphorus compounds such as diphosphorus pentasulfide (P ₂ S ₅ ) and simple phosphorus can be used without particular limitation as long as they are industrially produced and sold.

  The solid raw material containing lithium element, phosphorus element, and sulfur element preferably contains at least one of a lithium compound and a lithium metal simple substance and at least one of a phosphorus compound and a phosphorus simple substance. Among them, a combination of a lithium compound and a phosphorus compound is preferable, a combination of a lithium compound and phosphorus sulfide is more preferable, a combination of lithium sulfide and phosphorus sulfide is more preferable, and a combination of lithium sulfide and phosphorus pentasulfide is particularly preferable. .

The amount of the solid raw material containing lithium element and the solid raw material containing phosphorus element is not particularly limited, and may be appropriately determined based on a desired solid electrolyte. For example, when lithium sulfide (Li ₂ S) is used as a solid material containing lithium element and diphosphorus pentasulfide (P ₂ S ₅ ) is used as a solid material containing phosphorus element, Li ₂ S and P ₂ S ₅ are used. The ratio of Li ₂ S to the total is preferably in the range of 68 mol% or more and 95 mol% or less, more preferably in the range of 70 mol% or more and 94 mol% or less, and 72 mol% or more and 93 mol% from the viewpoint of obtaining a solid electrolyte having high chemical stability. % Is more preferable, and a range of 74 mol% or more and 92 mol% or less is particularly preferable.

  The solid raw material preferably further contains at least one halogen element such as fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). Chlorine (Cl), bromine (Br) And at least one of iodine (I) is preferable, and at least one of bromine (Br) and iodine (I) is more preferable. For example, it is preferable to include a halogen-containing compound represented by the following general formula (1).

In general formula (1), M is sodium (Na), lithium (Li), boron (B), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), germanium (Ge), Arsenic (As), Selenium (Se), Tin (Sn), Antimony (Sb), Tellurium (Te), Lead (Pb), Bismuth (Bi), or a combination of these elements with oxygen and sulfur elements Lithium (Li) or phosphorus (P) is preferable, and lithium (Li) is particularly preferable.
X is a halogen element selected from fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).
L is an integer of 1 or 2, and m is an integer of 1 to 10. When m is an integer of 2 or more and 10 or less, that is, when there are a plurality of X, X may be the same or different. For example, in SiBrCl ₃ described later, m is 4, and X is composed of different elements such as Br and Cl.

Specific examples of the halogen-containing compound represented by the general formula (1) include sodium halides such as NaI, NaF, NaCl, and NaBr, lithium halides such as LiF, LiCl, LiBr, and LiI, BCl ₃ , Boron halides such as BBr ₃ and BI ₃ , aluminum halides such as AlF ₃ , AlBr ₃ , AlI ₃ and AlCl ₃ , SiF ₄ , SiCl ₄ , SiCl ₃ , Si ₂ Cl ₆ , SiBr ₄ , SiBrCl ₃ , SiBr ₂ Cl _2, SiI ₄ and halogenated _{silicon, PF 3, PF 5, PCl} 3, PCl 5, POCl 3, PBr 3, POBr 3, PI 3, P 2 Cl 4, phosphorus halides such as P 2 _{I 4,} SF ₂ , SF ₄ , SF ₆ , S ₂ F ₁₀ , SCl ₂ , S ₂ Cl ₂ , S ₂ Br _2, etc. Sulfogenated sulfur, GeF ₄ , GeCl ₄ , GeBr ₄ , GeI ₄ , GeF ₂ , GeCl ₂ , GeBr ₂ , GeI _{2 and} other halogenated germanium, AsF ₃ , AsCl ₃ , AsBr ₃ , AsI ₃ , AsF _{5 and the} like _{arsenic, SeF 4, SeF 6, SeCl} 2, SeCl 4, Se 2 Br 2, SeBr 4 like halogenated _{selenium, SnF 4, SnCl 4, SnBr} 4, SnI 4, SnF 2, SnCl 2, SnBr 2, SnI Tin halides such as ₂ ; antimony halides such as SbF ₃ , SbCl ₃ , SbBr ₃ , SbI ₃ , SbF ₅ , SbCl ₅ , TeF ₄ , Te ₂ F ₁₀ , TeF ₆ , TeCl ₂ , TeCl ₄ , TeBr ₂ Tellurium halides such as TeBr ₄ and TeI ₄ , PbF ₄ , Pb _{Cl 4, PbF 2, PbCl 2} , PbBr 2, PbI 2 , etc. lead _{halide, BiF 3, BiCl 3, BiBr} 3, BiI halogenated bismuth such as _3.

Examples of the halogen-containing compounds include lithium halides such as lithium chloride (LiCl), lithium bromide (LiBr), and lithium iodide (LiI), phosphorus pentachloride (PCl ₅ ), phosphorus trichloride (PCl ₃ ), five Phosphorus halides such as phosphorus bromide (PBr ₅ ) and phosphorus tribromide (PBr ₃ ) are preferred. Among these, lithium halides such as lithium chloride (LiCl), lithium bromide (LiBr), and lithium iodide (LiI), and phosphorus tribromide (PBr ₃ ) are preferable, and lithium chloride (LiCl) and lithium bromide (LiBr) are preferable. ) And lithium iodide (LiI) are more preferable, and lithium bromide (LiBr) and lithium iodide (LiI) are particularly preferable. As the halogen-containing compound, one of the above compounds may be used alone, or two or more thereof may be used in combination, that is, at least one of the above compounds can be used.

  For example, when lithium bromide (LiBr) and lithium iodide (LiI) are used as the halogen-containing compound, the total usage ratio of lithium bromide (LiBr) and lithium iodide (LiI) in the solid raw material used for the production of the solid electrolyte Is not particularly limited as long as a desired solid electrolyte can be obtained. For example, it is preferably in the range of 3 mol% to 40 mol%, preferably in the range of 3 mol% to 35 mol%. It is more preferable that it is in the range of 3 mol% or more and 30 mol% or less. For example, in the range of 5 mol% to 28 mol%, in the range of 8 mol% to 28 mol%, in the range of 10 mol% to 28 mol%, in the range of 12 mol% to 28 mol%, and in the range of 15 mol% to 28 mol%. Inside is mentioned.

  Moreover, the ratio (LiBr / (LiI + LiBr)) of lithium bromide (LiBr) to the total of lithium bromide (LiBr) and lithium iodide (LiI) is not particularly limited, and any ratio is adopted. However, the lithium ion (LiBr) is replaced with lithium iodide (LiI) in the same manner, but the Li ion is comparable to or higher than that of the solid electrolyte (solid electrolyte as a comparison target). The ratio is preferably such that the conductivity can be obtained, and more preferably the ratio capable of obtaining higher Li ion conductivity than the solid electrolyte as a comparison target. The ratio of the lithium bromide (LiBr) is, for example, in the range of 1 mol% to 99 mol%, and preferably in the range of 5 mol% to 75 mol%. For example, the range of 20 mol% or more and 75 mol% or less, 40 mol% or more and 72 mol% or less, and 50 mol% or more and 70 mol% or less is mentioned.

The proportion of lithium iodide (LiI) in all the materials used for the production of the solid electrolyte is more than 3 mol% and less than 20 mol%, and the proportion of lithium bromide (LiBr) in all the materials is 3 mol% or more and 20 mol% or less. It is preferable that
In addition, when the solid electrolyte has a composition of a ((1-b) LiI · bLiBr) · (1-a) (cLi ₂ S · (1-c) P ₂ S ₅ ), a is the above LiI and LiBr. B corresponds to the above LiBr ratio, and c corresponds to the above Li ₂ S ratio.

  The particle size of the solid raw material is not particularly limited as long as it is a particle size that each of the solid raw materials normally has. For example, the particle size of lithium sulfide is 0.01 mm or more and 3 mm or less, and the particle size of diphosphorus pentasulfide is 0.01 mm or more and 3 mm or less. Moreover, the particle size of lithium bromide is 0.01 mm or more and 3 mm or less, and the particle size of lithium iodide is 0.01 mm or more and 3 mm or less. Thus, since the solid raw material that can be used in this embodiment is subjected to a reaction using shearing force, its particle size is wide, and a solid electrolyte is produced regardless of the particle size of the solid raw material. Can do. Here, the average particle diameter is a value measured using a laser diffraction particle size distribution measuring apparatus (for example, Mastersizer 2000 manufactured by Malvern Instruments Ltd).

  Said solid raw material may be used as it is or may be used in the form of a slurry with an organic solvent. In the present embodiment, in consideration of productivity and mass productivity, it is preferable that the organic solvent is not used as much as possible, and it is preferable to use the solid raw material as it is without using the organic solvent and to perform the reaction in a dry process. Here, “using an organic solvent” means intentionally using an organic solvent, for example, when there is an organic solvent that is accompanied by a solid raw material that cannot be completely removed in the production process. Is excluded.

  In the case of using an organic solvent, an aprotic solvent such as an aprotic polar solvent or an aprotic nonpolar solvent may be used. The amount of the organic solvent used is usually the amount of the solid raw material added to 1 L of the organic solvent. What is necessary is just to set it as the quantity used as 0.001 kg or more and 1 kg or less.

(Conditions for reaction of solid raw materials)
In the present embodiment, the reaction of the solid raw material has different reaction conditions depending on the properties of the solid electrolyte to be obtained, that is, whether to obtain an amorphous solid electrolyte or a crystalline solid electrolyte.
In this specification, an amorphous solid electrolyte is a halo pattern in which an X-ray diffraction pattern is substantially a peak other than a peak derived from a material in an X-ray diffraction measurement. The presence or absence is not questioned.
Further, in this specification, a crystalline solid electrolyte is a solid electrolyte in which a peak derived from a solid electrolyte is observed in an X-ray diffraction pattern in an X-ray diffraction measurement. Any material. That is, the crystalline solid electrolyte includes a crystal structure derived from the solid electrolyte, and even if a part thereof is a crystal structure derived from the solid electrolyte, the whole is a crystal structure derived from the solid electrolyte. It is also good. As long as the crystalline solid electrolyte has the X-ray diffraction pattern as described above, an amorphous solid electrolyte may be included in a part thereof.

In this embodiment, when an amorphous solid electrolyte is obtained, the temperature during the reaction is such that an amorphous solid electrolyte is easily obtained, the by-products and impurities in the powder aggregate are reduced, and the reaction is more homogeneous. From the viewpoint of obtaining a high-quality solid electrolyte, the crystallization temperature is preferably not higher than the crystallization temperature, more preferably −150 ° C. or higher and −1 ° C. or lower, further preferably −100 ° C. or higher and −5 ° C. or lower, particularly preferably -80 degreeC or more and -30 degrees C or less are preferable.
On the other hand, when a crystalline solid electrolyte is obtained, the temperature during the reaction is such that a crystalline solid electrolyte is easily obtained, and there are fewer by-products and impurities in the powder aggregate, resulting in a more homogeneous and high-quality solid. From the viewpoint of obtaining an electrolyte, the temperature is preferably higher than the crystallization temperature, more preferably 1 to 150 ° C., more preferably 5 to 100 ° C., more preferably 30 to 80 ° C. Further preferred.
Here, the crystallization temperature in the present specification is the crystallization temperature of the crystal structure of the solid electrolyte in the case where a crystalline solid electrolyte is obtained using the solid raw material, that is, the amorphous material obtained using the solid raw material. This means the crystallization temperature of the solid electrolyte and can be confirmed and measured by differential thermal analysis (DTA). For example, using a differential thermal analyzer (DTA device), the temperature showing the exothermic peak observed at the lowest temperature, which is measured by differential thermal analysis (DTA) under a temperature rising condition of 10 ° C./min, is crystallized. Temperature.

The crystallization temperature varies depending on the type of element constituting the solid electrolyte, the composition ratio, the difference in structure, and the like, and the crystallization temperature of the Li ₂ S—P ₂ S ₅ based amorphous solid electrolyte is, for example, 210 ° C. or higher and 340 ° C. The crystallization temperature of the Li ₂ S—P ₂ S ₅ —LiBr amorphous solid electrolyte is, for example, 170 ° C. or more and 290 ° C. or less, Li ₂ S—P ₂ S ₅ —LiI amorphous amorphous The crystallization temperature of the solid electrolyte is, for example, 140 ° C. or more and 260 ° C. or less, and the crystallization temperature of the Li ₂ S—P ₂ S ₅ —LiI—LiBr-based amorphous solid electrolyte is, for example, in the range of 140 ° C. or more and 260 ° C. or less. It is in.

  What is necessary is just to adjust the temperature at the time of reaction of a solid raw material so that it may become the said reaction temperature according to whether an amorphous solid electrolyte is obtained or a crystalline solid electrolyte is obtained. The effect of the manufacturing method of this embodiment that can suppress the local rise in temperature in the reaction vessel, that it is preferable to avoid crystallization as much as possible when trying to obtain an amorphous solid electrolyte, etc. In consideration, the manufacturing method of the present embodiment can be adopted as a manufacturing method for obtaining a crystalline solid electrolyte at a temperature higher than the crystallization temperature, but is more effective as a manufacturing method for obtaining an amorphous solid electrolyte at a temperature lower than the crystallization temperature. And preferably used.

(Reaction and reaction equipment using shear force)
In the production method of the present embodiment, the reaction of the solid raw material is performed by a reaction using a shearing force in at least one reaction vessel.
In the present embodiment, the “shearing force” means a force that is applied in an opposite direction in parallel to the surface when at least two particles contact each other on an arbitrary surface. In the present embodiment, the shear force is more specifically determined between powder aggregates, that is, powders such as unreacted solid raw materials, reactants (solid electrolytes, intermediates, byproducts), and impurities. This is due to contact between at least one kind of powders.

Hereinafter, the reaction using the shearing force will be specifically described with reference to FIG. 1 showing a preferred embodiment of the reaction equipment that can be used in the method for producing a solid electrolyte of the present embodiment.
The reaction facility shown in FIG. 1 includes a supply port 4, a discharge port 5, a device 3 for imparting a shearing force, and a reaction vessel 1 (as an example, a kneader is shown), from the discharge port. A cooling device that cools the discharged powder aggregate and a pipe that connects the reaction vessel 2 and the cooling device are provided. In the present embodiment, the reaction using the shearing force can be performed using, for example, the reaction apparatus 1 including the reaction vessel 2 and the device 3 that applies the shearing force.

The shearing force can be expressed by, for example, a single screw, a multi-screw, a combination of a rotating blade and a rotating or fixed blade, vibration, contact using a grinding medium, a rotor, and a combination thereof. That is, a uniaxial screw, a multiaxial screw, a mechanism combining a rotating blade and a rotating or fixed blade, a vibration generating mechanism, a collision generating mechanism using a pulverizing medium, a powder collision generating mechanism, a rotor, etc. A reaction using a shearing force can be performed using an apparatus that provides a combined mechanism and imparts a shearing force.
In the present embodiment, the device for applying the shearing force includes a single screw, a multiaxial screw, a mechanism that combines a rotating blade and a rotating or fixed blade from the viewpoint of applying the shearing force more efficiently. It is preferable.

Examples of the reaction apparatus including the reaction vessel and the above-described device for applying the shearing force provided in the vessel include a single-screw kneader having a single screw and a multi-screw kneader having a multi-screw (a general-purpose multi-purpose machine). Shaft kneader, KRC kneader (manufactured by Kurimoto Seiko Co., Ltd., etc.), lab plast mill (manufactured by Toyo Seiki Seisakusho Co., Ltd., etc.), kneader equipped with a mechanism combining a rotating blade and a rotating or fixed blade ( Miracle K.C.K (manufactured by Asada Tekko Co., Ltd.), vibration mills equipped with a vibration generating mechanism, ball mills equipped with a collision generating mechanism using grinding media, bead mills, agitating mills, and other various mills (general-purpose mill machines, High-speed planetary ball mill (Hiji (Kurimoto Co., Ltd.)), dry bead mill (Dry Star (Ashizawa Finetech Co., Ltd.)), media agitation mill (Attritor) Nippon Coke Kogyo Co., Ltd.)), equipment equipped with a mechanism for generating collisions between powders (for example, surface modification / pulverization device (Nanomeric Reactor (Techno Eye Co., Ltd.)), Hybridization (Co., Ltd.) Nara Machinery Co., Ltd.), a crushing rotor equipped with a rotor, and a device equipped with a rotating rotor (for example, nobilta, pulverizer, mechanofusion, cyclomix (all manufactured by Hosokawa Micron Co., Ltd.)).
These devices can generate mixing, convection, impact, etc. simultaneously with the shearing force, but can be used as a device for applying the shearing force in this embodiment as long as at least the shearing force can be applied. be able to.

In the present embodiment, a reaction apparatus including a reaction vessel and a device for applying a shearing force is such that at least one of a solid raw material and a powder aggregate supplied to the reaction apparatus is a powder aggregate in the reaction container. It is preferable to have a method of extruding and discharging. With such a system, the powder aggregate in the reaction vessel becomes denser and the opportunities for contact between the powders increase, so that shear force can be applied to the powder aggregate more efficiently. , It can make the reaction easier to proceed.
From this point of view, in this embodiment, as the reaction apparatus, a single-screw kneader equipped with a single screw, a multi-screw kneader equipped with a multi-screw, and a kneading equipped with a mechanism combining a rotating blade and a rotating or fixed blade. More preferred.

The shape of the reaction vessel is not particularly limited as long as it can be equipped with a device for applying a shearing force, and includes, for example, a single-axis kneader, a multi-axis kneader, and a mechanism that combines a rotating blade and a rotating or fixed blade. If it is a kneader, it may be a cylindrical shape, an elliptical cylinder shape, or the like, or may be a shape such as a cubic shape, a rectangular parallelepiped shape, a conical shape, or a quadrangular pyramid shape.
The volume of the reaction vessel may be appropriately selected according to the production scale of the solid electrolyte, and is not particularly limited. For example, it may be about 0.5 L to 1500 L, preferably 50 L to 1200 L.

  In the present embodiment, the filling rate of the powder aggregate in the reaction vessel is preferably 20% by volume or more from the viewpoint of more efficiently imparting a shear force to the powder aggregate and facilitating the reaction. Volume% or more is more preferable, 50 volume% or more is still more preferable, 75 volume% or more is further more preferable, and 80 volume% or more is particularly preferable. Here, the “filling rate of the powder aggregate in the reaction container” means the ratio of the volume of the powder aggregate present in the reaction container to the volume of the space where the powder aggregate can exist in the reaction container. More specifically, the ratio is the ratio of the volume of the powder aggregate to the volume obtained by subtracting the volume of the device to which the shearing force is applied from the volume of the reaction vessel.

The supply port and the discharge port provided in the reaction vessel are only required to have a structure capable of supplying and discharging the solid raw material and the powder aggregate. The environment in which the reaction apparatus is installed and the mode of the reaction equipment including the reaction apparatus These may be selected as appropriate.
For example, considering the ease of operation, the supply port preferably has a shape that can store the solid raw material and the powder aggregate once, for example, a hopper as shown in FIG. Here, the hopper may have an opening at least in part, and the solid raw material and the powder aggregate may be supplied from the opening. In addition, when the powder aggregate discharged from the reaction vessel is transferred in a pipe by a gas such as nitrogen and cooled by a cooling device and then supplied to the reaction vessel, a flange for connecting to the pipe, etc. It is only necessary to have a connection port of the following, and without performing gas transfer by piping, the reaction facility receives the powder aggregate discharged from the reaction container in the container, and after cooling, the powder aggregate is removed from the container. In the case of supplying from the supply port, an opening may be provided so that the powder aggregate can be easily supplied from the container.
Further, the discharge port may have a connection port such as a flange for connection with the pipe when the powder aggregate is gas-transferred through the pipe, and if the pipe is not provided, the powder aggregate If it is a shape that can be received by the container, there is no particular limitation, and considering the ease of collection of the powder aggregate, for example, a general-purpose discharge chute may be used.

Since the reaction of the solid raw material may be denatured when the obtained solid electrolyte comes into contact with water or oxygen, the supply of the solid raw material, the reaction, and the discharge of the powder aggregate are preferably performed in an inert gas atmosphere. In this case, examples of the inert gas include nitrogen and argon. Moreover, when carrying out gas transfer of a powder aggregate by piping, these inert gas is mentioned as gas used.
The reaction of the solid raw material is preferably performed in a dry atmosphere, for example, preferably performed in an atmosphere having a dew point of −90 ° C. or higher and −40 ° C. or lower, and performed in an atmosphere of a dew point of −90 ° C. or higher and −45 ° C. or lower. Is more preferable, and it is more preferable to perform in an atmosphere having a dew point of −90 ° C. or higher and −50 ° C. or lower. In order to realize this, there is a method of installing reaction equipment in a glove box or a dry room.

  Depending on the scale of the reaction equipment, it may not be installed in the glove box or dry room. In such a case, for example, the above inert gas is intermittently or continuously supplied to the reaction vessel and, if necessary, to the cooling device, the pipe connecting the reaction vessel and the cooling device, the solid raw material supply facility, etc. This method can also be realized by a method in which a solid raw material and a place through which a powder aggregate passes are made an inert gas atmosphere. When supplying to the reaction vessel, a supply port and a discharge port for supplying an inert gas may be provided in the reaction vessel.

(Cooling system)
In the present embodiment, it is necessary to cool the powder aggregate discharged from the reaction vessel and supply it to at least one of the reaction vessel and another reaction vessel. By cooling the powder aggregate and supplying it to the reaction vessel, a local increase in temperature in the reaction vessel is suppressed, and a homogeneous and high-quality solid electrolyte can be obtained with excellent productivity and mass productivity.

The cooling device that can be used for cooling the powder aggregate is not particularly limited as long as it can cool the powder aggregate. For example, a cooling apparatus that can directly or indirectly cool the powder aggregate is used. .
As a cooling device that directly cools using a refrigerant, for example, a device that directly supplies the above-mentioned inert gas or the like to a container containing the powder aggregate and directly cools it, and the powder aggregate can be gas-transferred. A pipe etc. are mentioned. Moreover, what cools indirectly using a refrigerant | coolant includes an air cooling jacket, a water cooling jacket, an air cooling heat exchanger, a water cooling heat exchanger, etc.
These cooling devices may be appropriately selected in consideration of the environment in which the cooling device is installed, the mode of the reaction equipment including the cooling device, and the like. For example, when using the piping shown in FIG. Cooling with gas for transferring the inside, a cooling device such as a jacket, and a combination of these may be employed. When piping is not used, the container that received the discharged powder aggregate is filled with gas or the like. A device that can be directly supplied and cooled can be used.

(Plumbing)
In the present embodiment, when a pipe connecting the reaction vessel and the cooling device is used, the pipe material is not particularly limited, and a metal pipe such as a resin tube or stainless steel can be used.
When the piping is adopted, the transfer between the reaction vessel for the solid raw material and the powder aggregate by the piping and the cooling device can be performed by gas transfer using gas. In this case, it is preferable to use the above inert gas as the gas.

(Composition of reaction equipment)
In this embodiment, as the reaction equipment, as shown in FIG. 1, an input port, an exhaust port, one reaction device including a device for applying a shearing force and a reaction vessel, and a set of powders discharged from the exhaust port Examples include a cooling device for cooling an object, and a facility having a pipe connecting the reaction device and the cooling device. The configuration shown in FIG. 1 is a single reaction vessel, and the powder aggregate discharged from the discharge port is cooled and supplied to the reaction vessel (also referred to as “configuration 1”) in this embodiment. It is an example of a preferred embodiment.
In the present embodiment, not only the configuration using the piping shown in FIG. 1 but also the configuration without using the piping, more specifically, the powder aggregate discharged from the discharge port without using the piping is used as the container. Then, the powder aggregate in the container may be cooled, and the powder aggregate in the container may be supplied to the reaction container from the supply port.

In the present embodiment, there may be two or more reaction vessels. A configuration in the case of two or more reaction vessels will be described with reference to FIGS. When there are two or more reaction vessels, the simplest configuration is to cool the powder aggregate discharged from one reaction vessel (reaction vessel A) shown in FIG. It is the structure (it is also called "the structure 2a") supplied to another reaction container (reaction container B).
In addition to the configuration 2a, the configuration shown in FIG. 2B is a configuration 2b-1 in which the powder aggregate discharged from one reaction vessel (reaction vessel A) is returned to the one reaction vessel (reaction vessel A). Configuration 2b-2 for supplying the powder aggregate discharged from one reaction vessel (reaction vessel B) to another reaction vessel (reaction vessel A) and discharged from one reaction vessel (reaction vessel B) The configuration having the configuration 2b-3 for supplying the powder aggregate to the one reaction vessel (reaction vessel B) at the same time (also referred to as “configuration 2b”). Here, the configuration 1 can be said to be the same configuration as the configurations 2b-1 and 2b-3 in that the powder aggregate discharged from the reaction vessel is supplied to the same reaction vessel.
Thus, in this embodiment, the structure which cools the powder aggregate discharged | emitted from one reaction container, and supplies to at least one of this one reaction container and another reaction container is employable.

  In the present embodiment, for example, as in the configuration shown in FIG. 2B, the configuration 2b-1, the configuration in which the powder aggregate discharged from one reaction vessel is supplied to the one reaction vessel in the configuration 2a. The reaction equipment can be configured by applying the configuration 2b-2 for supplying the powder aggregate discharged from the reaction vessel to another reaction vessel in combination as appropriate. For example, as shown in FIG. 3-a, a cooling device between one reaction vessel and another reaction vessel (reaction vessel A and B) is not provided, and the other reaction vessel (reaction vessel B) is discharged. A configuration in which the collected powder aggregate is cooled and returned to the other reaction vessel (reaction vessel B), for example, one reaction vessel and another reaction vessel (reaction vessel as shown in FIG. 3B) A configuration in which the cooling device between A and B) is not provided, and the powder aggregate discharged from the other reaction vessel (reaction vessel B) is cooled and returned to the one reaction vessel (reaction vessel A). Can also be adopted.

In the production method of the present embodiment, the temperature in the reaction vessel is more reliably controlled, the local increase in the temperature in the reaction vessel is suppressed, and a homogeneous and high-quality solid electrolyte is produced with excellent productivity and mass production. It is preferable to have a cooling device that can cool the powder aggregate discharged from each reaction vessel. That is, from such a viewpoint, in the manufacturing method of the present embodiment, the mode shown in FIGS. 2-a and 2-b is preferable to the mode shown in FIGS.
On the other hand, when the temperature of the powder aggregate discharged from the reaction vessel is low, for example, when the temperature is relatively easy, such as when the temperature is 60 ° C. or lower, the reaction equipment is simpler and less expensive. In view of the above, a configuration with few cooling facilities as shown in FIGS. Thus, in this embodiment, what kind of structure of the reaction equipment is used may be appropriately determined and adopted according to the temperature of the powder aggregate discharged from the reaction vessel.

(Conditions for operation of reaction equipment)
In this embodiment, the temperature of the powder aggregate discharged from the reaction vessel is preferably 35 ° C. or higher and 150 ° C. or lower, more preferably 40 ° C. or higher and 120 ° C. or lower, when obtaining an amorphous solid electrolyte, 45 ° C. More preferably, the temperature is 90 ° C. or lower. When obtaining a crystalline solid electrolyte, the temperature is preferably higher than 50 ° C, preferably 60 ° C or higher and 250 ° C or lower, more preferably 70 ° C or higher and 230 ° C or lower, and further preferably 70 ° C or higher and 210 ° C or lower. . By setting the above temperature range, the reaction of the solid raw material proceeds more favorably, the desired solid electrolyte can be easily obtained, the by-products and impurities in the powder aggregate can be reduced, and more homogeneous. A high quality solid electrolyte can be obtained. Here, the temperature of the powder aggregate is the temperature measured by installing a thermometer at the outlet.

  In this embodiment, when cooling the powder aggregate discharged from the reaction container at the above temperature, the temperature of the powder aggregate after cooling is the temperature of the powder aggregate discharged from the reaction container. The temperature is preferably from −100 ° C. to −5 ° C., more preferably from −80 ° C. to −10 ° C. When the temperature of the powder aggregate after cooling is within the above range, a local increase in the temperature in the reaction vessel is suppressed, and a homogeneous and high-quality solid electrolyte is obtained with excellent productivity and mass productivity. Can do. Here, the temperature of the powder aggregate is the temperature measured by installing a thermometer at the outlet of the cooling device used for cooling or near the outlet. Moreover, when reaction equipment does not use piping, a thermometer is inserted in the powder aggregate immediately after cooling, and it is set as the measured temperature.

  The reaction time of the solid raw material varies depending on the type of element constituting the solid electrolyte to be obtained, the composition ratio, the difference in structure, and the temperature at the time of reaction, and therefore may be adjusted as appropriate, preferably 5 minutes or more and 200 hours or less, More preferably, it is 10 minutes or more and 150 hours or less, More preferably, it is 1 hour or more and 120 hours or less. Here, the “reaction time of the solid raw material” means the total time that the powder aggregate stays in the reaction vessel. Therefore, in the present embodiment, the total time that the powder aggregate stays in the reaction vessel is preferably within the above time range. By setting such a reaction time, the reaction of the solid raw material proceeds more favorably, the desired solid electrolyte can be easily obtained, the by-products and impurities in the powder aggregate can be reduced, and more homogeneous A high quality solid electrolyte can be obtained.

  The degree of progress of the reaction of the solid raw material can be grasped by the increase or decrease of the peak derived from the solid raw material of the powder aggregate, and it can be considered that the reaction has sufficiently progressed when the peak is no longer detected. Here, “the peak is no longer detected” means that the peak intensity derived from the solid raw material is at least 10% or less of the maximum peak intensity among the peaks derived from the solid electrolyte. From the viewpoint of obtaining a more homogeneous and high-quality solid electrolyte, the peak intensity derived from the solid raw material with respect to the maximum peak intensity among the peaks derived from the solid electrolyte is preferably 5% or less, more preferably 3% or less, particularly below the detection limit. Preferably, it is not substantially detected.

  The powder aggregate at the time when the peak is no longer detected mainly contains a solid electrolyte and does not substantially contain a solid raw material. According to the manufacturing method of the present embodiment, the content of the solid electrolyte in the powder aggregate in which no peak is detected, that is, the powder aggregate that can be a solid electrolyte that is a product of the manufacturing method of the present embodiment, is 90 mass. % Or more, 95 mass% or more, 97 mass% or more, and further 99 mass% or more. Thus, the solid electrolyte obtained by the manufacturing method of this embodiment becomes a high-quality solid electrolyte with high purity.

In the present embodiment, X-ray diffraction measurement of the powder aggregate is performed, and after confirming that the peak derived from the solid raw material is no longer detected, the powder aggregate may be recovered to be a solid electrolyte. Know the reaction time at the point when the “peak is no longer detected” according to the temperature of the solid raw material, the powder aggregate discharged from the reaction vessel, etc., and the powder aggregate after a predetermined reaction time has elapsed May be recovered as a solid electrolyte.
Further, in the present embodiment, after supplying the solid raw material once, the solid raw material is not replenished until the above reaction sufficiently proceeds, and after the reaction proceeds, the powder aggregate can be recovered and used as a solid electrolyte. It is also possible to obtain a solid electrolyte by collecting at least a part of the powder aggregate while replenishing the solid raw material.

(Heating of powder aggregate)
According to the manufacturing method of this embodiment, an amorphous solid electrolyte and a crystalline solid electrolyte can be obtained by adjusting the reaction temperature. In order to obtain a crystalline solid electrolyte, the reaction temperature may be set accordingly. After obtaining an amorphous solid electrolyte, the amorphous solid electrolyte is heated to obtain a crystalline solid electrolyte. It can also be obtained. Even when a crystalline solid electrolyte is obtained by adjusting the reaction temperature, the crystalline solid electrolyte can be heated from the viewpoint of further improving the crystallinity. That is, the manufacturing method of this embodiment can further include heating the powder aggregate.

  In the heating of the powder aggregate, the heating temperature of the amorphous solid electrolyte is subjected to differential thermal analysis (DTA) using a differential thermal analyzer (DTA device) under a temperature rising condition of 10 ° C./min. The starting point of the exothermic peak observed on the lowest temperature side is preferably ± 40 ° C., more preferably ± 30 ° C., and further preferably ± 20 ° C.

The heating time is not particularly limited as long as a desired crystalline solid electrolyte is obtained, but is preferably within a range of 1 minute to 24 hours, for example, within a range of 1 minute to 10 hours. Is more preferable.
The heating method is not particularly limited, and examples thereof include a method using a vacuum heating apparatus, an argon gas atmosphere furnace, and a baking furnace. The heating is preferably performed in an inert gas atmosphere (for example, a nitrogen atmosphere or an argon atmosphere) or a reduced pressure atmosphere (particularly in a vacuum). This is because deterioration (for example, oxidation) of the crystalline solid electrolyte can be prevented.

(Solid electrolyte)
Examples of the solid electrolyte obtained by the production method of the present embodiment include alkali metals such as lithium, sodium, potassium, rubidium, cesium, and francium, and alkaline earth metals such as beryllium, magnesium, calcium, strontium, barium, and radium. Examples thereof include amorphous or crystalline solid electrolytes containing at least one selected element as a conductive species. Among these, as an element, when ion conductivity is high and the high output of a battery is considered, alkali metals, such as lithium, sodium, potassium, rubidium, cesium, and francium, and beryllium are preferable, and lithium is especially preferable.

Examples of solid electrolytes include oxide solid electrolytes and sulfide solid electrolytes, but ionic conductivity is high, and sulfide solid electrolytes are preferable in view of high battery output.
Examples of the sulfide solid electrolyte include a sulfide solid electrolyte containing lithium element, phosphorus element, and sulfur element, a sulfide solid electrolyte containing lithium element, phosphorus element, sulfur element, and halogen element, lithium element, phosphorus element, Sulfide solid electrolyte containing elemental sulfur and bromine, sulfide solid electrolyte containing elemental lithium, phosphorus, sulfur, and iodine, sulfide containing elemental lithium, phosphorus, sulfur, bromine, and iodine Solid electrolytes.

(Amorphous solid electrolyte)
More specifically, examples of the amorphous sulfide solid electrolyte include Li ₂ S—P ₂ S ₅ , Li ₂ S—P ₂ S ₅ —LiI, Li ₂ S—P ₂ S ₅ —LiCl, Li _{2. S-P 2 S 5 -LiBr,} Li 2 S-P 2 S 5 -LiI-LiBr, Li 2 S-P 2 S 5 -Li 2 O, Li 2 S-P 2 S 5 -Li 2 O-LiI, _{Li 2 S-SiS 2, Li} 2 S-SiS 2 -LiI, Li 2 S-SiS 2 -LiBr, Li 2 S-SiS 2 -LiCl, Li 2 S-SiS 2 -B 2 S 3 -LiI, Li 2 _{S-SiS 2 -P 2 S 5} -LiI, Li 2 S-B 2 S 3, Li 2 S-P 2 S 5 -Z m S n (m, n is the number of positive .Z is, Si, Ge, Zn, Ga, Sn, or Al.), Li ₂ S—GeS ₂ , Li ₂ S— _{SiS 2 -Li 3 PO 4, Li} 2 S-SiS 2 -Li x MO y (x, y is a positive number .M is, P, Si, Ge, B , Al, Ga, either an In.), li ₁₀ GeP ₂ S _12, and the like.

As the amorphous oxide solid electrolyte, Li ₂ O—B ₂ O ₃ —P ₂ O ₅ , Li ₂ O—SiO ₂ , LiLaTaO (for example, Li ₅ La ₃ Ta ₂ O ₁₂ ), LiLaZrO ( For example, Li ₇ La ₃ Zr ₂ O ₁₂ ), LiBaLaTaO (eg, Li ₆ BaLa ₂ Ta ₂ O ₁₂ ), Li _{1 + x} Si _x P _1-x O ₄ (0 ≦ x <1, eg, Li _3.6 Si _{0 .6} P _0.4 O ₄ ), Li _{1 + x} Al _x Ge _2-x (PO ₄ ) ₃ (0 ≦ x ≦ 2), Li _{1 + x} Al _x Ti _2-x (PO ₄ ) ₃ (0 ≦ x ≦ 2) ), Li ₃ PO _{(4-3 / 2x)} N _x (0 ≦ x <1), and the like.
The kind of element which comprises the solid electrolyte obtained with the manufacturing method of this embodiment can be confirmed with an ICP emission spectrometer, for example.

(Crystalline solid electrolyte)
More specifically, the crystal structure of the crystalline solid electrolyte is, for example, Li ₃ PS ₄ crystal structure, Li ₄ P ₂ S ₆ crystal structure, Li ₇ PS ₆ crystal structure, Li ₇ P ₃ S ₁₁ crystal structure, Li _{4-x Ge 1-x P} x S 4 based Chiori axicon Region II (thio-LISICON Region II) type crystal structure (Kanno et al., see Journal of The Electrochemical Society, 148 ( 7) A742-746 (2001)), Li Crystal structure similar to _4-x Ge _1-x P _x S ₄ type thio-LISICON Region II type (see Solid State Ionics, 177 (2006), 2721-2725), Aldilodite crystal structure (Adam , Solid tate Ionics, and the like (see 230.72.2013)).

In the X-ray diffraction measurement using CuKα rays, the diffraction peak of the Li ₃ PS ₄ crystal structure is, for example, around 2θ = 17.5 °, 18.3 °, 26.1 °, 27.3 °, 30.0 °. The diffraction peak of the Li ₄ P ₂ S ₆ crystal structure appears at, for example, 2θ = 16.9 °, 27.1 °, and 32.5 °, and the diffraction peak of the Li ₇ PS ₆ crystal structure, for example, 2θ = 15.3 °, 25.2 °, 29.6 °, 31.0 °, and the diffraction peak of the Li ₇ P ₃ S ₁₁ crystal structure is, for example, 2θ = 17.8 °, 18.5 °, Appears in the vicinity of 19.7 °, 21.8 °, 23.7 °, 25.9 °, 29.6 °, 30.0 °, and Li _4-x Ge _1-x P _x S ₄ series thiolysicon region II The diffraction peak of the (thio-LISICON Region II) type crystal structure is, for example, 2θ = 20.1 °, A diffraction peak having a crystal structure similar to that of Li _4-x Ge _1-x P _x S ₄ system thiolithic region II type appears near 23.9 ° and 29.5 °, for example, 2θ = 20.2, appearing near 23.6 °. Note that these peak positions may move back and forth within a range of ± 0.5 °.

Moreover, as a crystal structure of the crystalline solid electrolyte, an aldilodite-type crystal structure is also exemplified. As the aldilodite type crystal structure, for example, Li ₇ PS ₆ crystal structure; Li ₇ PS ₆ structural skeleton, and a composition formula Li _7-x P _1-y Si _{y formed} by substituting part of P with Si Crystal structure represented by S ₆ and Li _{7 + x} P _1-y Si _y S ₆ (x is −0.6 to 0.6, y is 0.1 to 0.6); Li _7-x-2y PS _{6− x-y Cl x (0.8 ≦} x ≦ 1.7,0 <y ≦ -0.25x + 0.5) crystal structure represented _{by; Li 7-x PS 6-} x Ha x (Ha is Cl or Br, a crystal structure in which x is preferably 0.2 to 1.8).

Compositional formulas Li _7-x P _1-y Si _y S ₆ and Li _{7 + x} P _1-y Si _y S ₆ (which have a structural skeleton of Li ₇ PS ₆ described above and in which a part of P is substituted with Si ( X is -0.6 to 0.6, y is 0.1 to 0.6), and the crystal structure is cubic or orthorhombic, preferably cubic. X-ray diffraction measurement using CuKα rays At 2θ = 15.5 °, 18.0 °, 25.0 °, 30.0 °, 31.4 °, 45.3 °, 47.0 °, and 52.0 °. Has a peak. The crystal structure represented by the composition formula Li _7-x-2y PS _6- xyCl _x (0.8 ≦ x ≦ 1.7, 0 <y ≦ −0.25x + 0.5) is preferably cubic. In the X-ray diffraction measurement using CuKα rays, 2θ = 15.5 °, 18.0 °, 25.0 °, 30.0 °, 31.4 °, 45.3 °, 47. It has peaks appearing at 0 ° and 52.0 ° positions. The crystal structure represented by the above composition formula Li _7-x PS _6-x Ha _x (Ha is Cl or Br, x is preferably 0.2 to 1.8) is preferably cubic and CuKα ray. In the X-ray diffraction measurement using, mainly 2θ = 15.5 °, 18.0 °, 25.0 °, 30.0 °, 31.4 °, 45.3 °, 47.0 °, and 52 It has a peak that appears at the 0 ° position.
Note that these peak positions may move back and forth within a range of ± 0.5 °.

Further, .2.4 The crystalline structure of the crystalline solid electrolyte, the composition formula _{Li x Si y P z S a} Ha w (Ha , including Br, Cl, or more or one or two of the I and F < (Xy) / (y + z) <3.3), the S content is 55 to 73% by mass, the Si content is 2 to 11% by mass, and the Ha element content is 0.02. What is more than mass%, more preferably, Li-Si-PS which appears at the positions of 2θ = 20.2 °, 24.0 ° and 29.7 ° in the X-ray diffraction measurement using CuKα ray. And a crystal structure having a peak derived from a type crystal structure and a peak appearing at a position of 2θ = 24.8 ° to 26.1 °. Note that these peak positions may move back and forth within a range of ± 0.5 °.

Although there is no restriction | limiting in particular as a shape of the solid electrolyte obtained by the manufacturing method of this embodiment, For example, a particulate form can be mentioned. The average particle diameter (D ₅₀ ) of the particulate amorphous solid electrolyte is preferably in the range of 0.1 μm to 50 μm, for example. The average particle size (D ₅₀ ) is a particle size at which 50% of the total particle size is accumulated from the smallest particle size when drawing a particle size distribution integration curve, and the volume distribution is, for example, laser diffraction / It can be measured using a scattering type particle size distribution measuring device.

(Use of solid electrolyte)
The solid electrolyte obtained by the manufacturing method of this embodiment has high ionic conductivity, excellent battery performance, and is suitably used for batteries. The use of lithium element as the conductive species is particularly suitable. The solid electrolyte obtained by the production method of the present embodiment may be used for the positive electrode layer, the negative electrode layer, or the electrolyte layer. Each layer can be manufactured by a known method.
Moreover, it is preferable that the said battery uses a collector other than a positive electrode layer, an electrolyte layer, and a negative electrode layer, and a well-known thing can be used for a collector. For example, a layer coated with Au or the like that reacts with the solid electrolyte, such as Au, Pt, Al, Ti, or Cu, can be used.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited at all by these examples.

Example 1
In the configuration shown in FIG. 1, the reaction apparatus is a twin-screw kneader (“S1 KRC kneader (product name)”, paddle diameter: φ25 mm, manufactured by Kurimoto Steel Corporation, volume (excluding the volume of the shaft and paddle part) : 0.12 L), a feeder (“Micron Feeder (product name)”, manufactured by Aisin Nano Technologies Co., Ltd.) was provided as a supply port in this biaxial kneader, and was installed in a glove box filled with nitrogen. A mixture of lithium sulfide (Li ₂ S) 57.416 g and diphosphorus pentasulfide (P ₂ S ₅ ) 92.484 g (Li ₂ S: P ₂ S ₅ = 75: 25 (molar ratio)) is used as a solid raw material, The material was supplied from the feeder to the supply port of the kneader, and kneading was started at an actual power of 120 W and a screw rotation speed of 210 rpm. The solid raw material was supplied from the supply port, and a powder aggregate at 50 ° C. was discharged from the discharge port after about 30 minutes. This was collected in a stainless steel container. After the discharged powder aggregate is injected with nitrogen and cooled to 30 ° C., the operation of returning to the feeder and kneading is repeated (reaction time (passage time of the powder aggregate in the biaxial kneader): about 100 Time), the powder aggregate was recovered. The powder aggregate was returned before the solid raw material in the feeder ran out. After the reaction, the powder aggregate was about 50 g of the powder aggregate in the biaxial kneader and the bulk density was 0.5 g / cc. Thus, the filling rate was 70% or more.
When powder X-ray analysis (XRD) measurement of the obtained powder aggregate was performed, peaks of lithium sulfide (Li ₂ S) and diphosphorus pentasulfide (P ₂ S ₅ ) were hardly detected, and a halo pattern was observed. It was confirmed that the powder aggregate was an amorphous solid electrolyte. In addition, the amorphous solid electrolyte obtained in this example was subjected to differential thermal analysis (DTA) under a temperature rising condition of 10 ° C./min using a differential thermal analyzer (DTA device) to obtain a crystallization temperature. (Tc) was 230 ° C.

(Example 2)
In Example 1, the solid raw materials were 41.272 g of lithium sulfide (Li ₂ S), 66.552 g of diphosphorus pentasulfide (P ₂ S ₅ ), 20.802 g of lithium bromide (LiBr), and lithium iodide (LiI). mixture of _{21.374g (Li 2 S: P 2} S 5: LiBr: LiI = 56.25: 18.75: 15.00: 10.00 ( molar ratio)) except that the in the same manner as in example 1 A powder aggregate was obtained.
When powder X-ray analysis (XRD) measurement of the obtained powder aggregate was performed, some lithium bromide (LiBr) peaks were detected, but other lithium sulfide (Li ₂ S), diphosphorus pentasulfide The peaks of (P ₂ S ₅ ) and lithium iodide (LiI) were scarcely detected, exhibiting a halo pattern, and were confirmed to be an amorphous solid electrolyte. The obtained powder aggregate was heat-treated at 200 ° C. for 3 hours, and the ionic conductivity measured by the above method was 4 × 10 ⁻³ S / cm.
The amorphous solid electrolyte obtained in this example was subjected to differential thermal analysis (DTA) under a temperature increase condition of 10 ° C./min using a differential thermal analyzer (DTA device), and measured glass crystals. The conversion temperature (Tc) was 170 ° C.

(Comparative Example 1)
A powder aggregate was obtained in the same manner as in Example 1 except that the powder aggregate was not cooled in Example 1.
When powder X-ray analysis (XRD) measurement of the obtained powder aggregate was performed, a crystallization peak (βLi ₃ PS ₄ etc.) related to the crystal structure derived from the solid electrolyte was confirmed, and a part was crystallized. A homogeneous solid electrolyte was not obtained.

(Comparative Example 2)
In Example 2, a powder aggregate was obtained in the same manner as in Example 2 except that the powder aggregate was not cooled.
When X-ray powder analysis (XRD) measurement of the obtained reaction product was performed, a crystallization peak (thio-LISICON Region II, etc.) related to the crystal structure derived from the solid electrolyte was confirmed, and a part was crystallized. Was confirmed.

  From the results of the examples, according to the production method of the present embodiment, in the reaction of the solid raw material using the shearing force, the homogeneous and high-quality solid is obtained by a simple operation of cooling the powder aggregate and returning it to the feeder. It was confirmed that an electrolyte was obtained. On the other hand, in Comparative Examples 1 and 2 that were not cooled, it was confirmed that some of them were crystallized and a homogeneous solid electrolyte could not be obtained.

  According to the manufacturing method of this embodiment, it is possible to obtain a homogeneous and high-quality amorphous and crystalline solid electrolyte with excellent productivity and mass productivity. These amorphous and crystalline solid electrolytes have high ionic conductivity, have excellent battery performance, and are suitably used for batteries. The use of lithium element as the conductive species is particularly suitable.

1. Reactor 1A. Reactor A
1B. Reactor B
2. Reaction vessel 2A. Reaction vessel A
2B. Reaction vessel B
3. 3. Equipment for applying shear force Supply port 5. Vent

Claims (16)

  A method for producing a solid electrolyte in which a solid raw material is reacted in at least one reaction vessel, wherein the reaction is a reaction using shearing force, the powder aggregate discharged from the reaction vessel is cooled, and the reaction vessel And supplying to at least one of the other reaction vessels.   The method for producing a solid electrolyte according to claim 1, wherein the number of the reaction containers is one, and the powder aggregate is cooled and supplied to the reaction container.   The number of the reaction containers is two or more, the powder aggregate discharged from one reaction container is cooled, and the powder aggregate is supplied to at least one of the one reaction container and another reaction container. 2. A method for producing a solid electrolyte according to 1.   The manufacturing method of the solid electrolyte of any one of Claims 1-3 using the reaction apparatus provided with the said reaction container and the apparatus which provides a shear force to a solid raw material.   5. The solid electrolyte according to claim 4, wherein the device for applying the shearing force is a device including at least one selected from a single screw, a multi-screw, and a mechanism in which a rotating blade and a rotating or fixed blade are combined. Production method.   The method for producing a solid electrolyte according to any one of claims 1 to 5, wherein a filling rate of the powder aggregate in the reaction vessel is 20% by volume or more.   The reaction apparatus has a system in which at least one of a solid raw material and a powder aggregate supplied to the reaction apparatus extrudes and discharges the powder aggregate in the reaction vessel. The manufacturing method of the solid electrolyte of any one of these.   The temperature of the powder aggregate discharged | emitted from the said reaction container is 35 to 150 degreeC, The manufacturing method of the solid electrolyte of any one of Claims 1-7.   The method for producing a solid electrolyte according to claim 8, wherein the temperature of the powder aggregate after cooling is not lower than -100 ° C and not higher than -5 ° C of the temperature of the powder aggregate discharged from the reaction vessel.   The method for producing a solid electrolyte according to claim 1, wherein the cooling is performed directly or indirectly using a refrigerant.   The manufacturing method of the solid electrolyte of any one of Claims 1-10 in which the said solid raw material contains a lithium element, a phosphorus element, and a sulfur element.   The method for producing a solid electrolyte according to claim 11, wherein the solid material includes at least one of a lithium compound and a lithium metal simple substance, and at least one of a phosphorus compound and a phosphorus simple substance.   The method for producing a solid electrolyte according to claim 11 or 12, wherein the solid raw material contains lithium sulfide and phosphorus sulfide.   The method for producing a solid electrolyte according to claim 11, wherein the solid raw material further contains a halogen element.   The method for producing a solid electrolyte according to claim 14, wherein the halogen element is at least one of bromine and iodine.   The method for producing a solid electrolyte according to claim 14 or 15, wherein the solid raw material contains at least one of lithium bromide and lithium iodide.