JP2018156835A - Method for manufacturing inorganic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an inorganic material, which enables a continuous process and is superior in productivity.SOLUTION: A method for manufacturing an inorganic material according to the present invention is one for manufacturing an inorganic material to be obtained by causing two or more kinds of inorganic compounds to chemically react with each other by a mechanical treatment. The method comprises: a preparation step of preparing an inorganic composition including the two or more inorganic compounds; and a vitrification step of performing a mechanical treatment on the inorganic composition by a pulverizer arranged to utilize a combination of a shear stress and a compressive stress, thereby vitrifying the inorganic composition while causing the two or more inorganic compounds to chemically react with each other.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing an inorganic material.

  Lithium ion batteries are generally used as a power source for small portable devices such as mobile phones and notebook computers. Recently, in addition to small portable devices, lithium ion batteries have begun to be used as power sources for electric vehicles and power storage.

  An electrolyte solution containing a flammable organic solvent is used in a lithium ion battery currently on the market. On the other hand, a lithium ion battery (hereinafter also referred to as an all-solid-state lithium ion battery) in which the electrolyte is changed to a solid electrolyte to make the battery completely solid does not use a flammable organic solvent in the battery. It is considered that the manufacturing cost and productivity are excellent. As a solid electrolyte material used for such a solid electrolyte, for example, a sulfide-based solid electrolyte material is known.

For example, Patent Document 1 (Japanese Patent Laid-Open No. 2016-27545) has a peak at a position of 2θ = 29.86 ° ± 1.00 ° in X-ray diffraction measurement using CuKα rays, and Li _{2y + 3} PS ₄ ( A sulfide-based solid electrolyte material having a composition of 0.1 ≦ y ≦ 0.175) is described.

JP 2016-27545 A

In general, an inorganic solid electrolyte material is a process of vitrifying an inorganic composition containing two or more inorganic compounds as raw materials for an inorganic solid electrolyte material by mechanical treatment using a ball mill or a bead mill. It is obtained through.
Here, a ball mill or a bead mill is a hard ball or bead formed from a ceramic material or the like and an inorganic composition placed in a cylindrical container and rotated so that the hard ball or bead collides with the inorganic composition. This is a device that vitrifies the inorganic composition by applying energy.
However, in the method in which the inorganic composition is vitrified using a ball mill, a bead mill, etc., the inorganic composition adheres to the wall surface in the container. It was necessary to scrape off the inorganic composition adhering to the surface. Furthermore, after the vitrification of the inorganic composition is completed, an operation for separating the vitrified inorganic composition from a ball mill, a bead mill or the like is necessary.
From the above, according to the study by the present inventors, it is difficult to continuously vitrify the inorganic composition by mechanically processing it using a ball mill, a bead mill or the like, which is very time consuming and productive. It became clear that it was bad. That is, the manufacturing method of the inorganic material including the step of vitrifying the inorganic composition as described above is not suitable for a continuous process and is not suitable for industrial production.

  This invention is made | formed in view of the said situation, and provides the manufacturing method of the inorganic material in which the continuous process was possible and excellent in productivity.

  The present inventors have intensively studied to achieve the above-mentioned problems. As a result, it was found that by performing a vitrification process of an inorganic composition using a pulverizing apparatus that combines shear stress and compressive stress, a continuous process becomes possible and productivity of the inorganic material can be improved, thereby completing the present invention. It came.

According to the present invention,
A production method for producing an inorganic material obtained by chemically reacting two or more kinds of inorganic compounds by mechanical treatment,
A preparation step of preparing an inorganic composition containing two or more inorganic compounds;
A vitrification step of vitrifying the inorganic composition while chemically reacting two or more of the inorganic compounds by mechanically treating the inorganic composition using a pulverizing apparatus that combines shear stress and compressive stress. ,
A method for producing an inorganic material comprising

  ADVANTAGE OF THE INVENTION According to this invention, the continuous process is possible and the manufacturing method of the inorganic material excellent in productivity can be provided.

It is sectional drawing which shows an example of the structure of the grinding | pulverization apparatus of embodiment which concerns on this invention. It is sectional drawing which shows an example of the structure of the grinding | pulverization apparatus of embodiment which concerns on this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In all the drawings, similar constituent elements are denoted by common reference numerals, and description thereof is omitted as appropriate. “A to B” in the numerical range represents A or more and B or less unless otherwise specified.

First, the manufacturing method of the inorganic material which concerns on this embodiment is demonstrated.
The manufacturing method of the inorganic material which concerns on this embodiment is a manufacturing method for manufacturing the inorganic material obtained by making 2 or more types of inorganic compounds chemically react by mechanical treatment, Comprising: 2 or more types of inorganic compounds are used. Using the preparatory process (A) which prepares the inorganic composition containing, and the grinding | pulverization apparatus which combined the shear stress and the compressive stress, the said inorganic composition is mechanically processed, and two or more said inorganic compounds are chemically reacted. Vitrification step (B) for vitrifying the inorganic composition.

According to the method for producing an inorganic material according to the present embodiment, it is not necessary to use a ball mill, a bead mill, or the like by using a pulverizing apparatus that combines shear stress and compressive stress, and the inorganic material is inorganic from the wall surface in the container during the production process. The operation of scraping off the composition and the operation of separating the vitrified inorganic composition from a ball mill, a bead mill or the like are unnecessary, and continuous mechanical treatment is possible. Moreover, vitrification of an inorganic composition can fully be advanced by combining a shear stress and a compressive stress.
As mentioned above, the manufacturing method of the inorganic material which concerns on this embodiment can vitrify an inorganic composition continuously. That is, the inorganic material manufacturing method according to the present embodiment is capable of a continuous process and is excellent in productivity.

  Hereinafter, each step will be described in detail.

(Step of preparing an inorganic composition (A))
First, an inorganic composition containing two or more inorganic compounds is prepared.
As the inorganic compound, two or more compounds that chemically react with each other by mechanical treatment to generate a new inorganic material are used. These inorganic compounds can be appropriately selected according to the inorganic material to be generated.
In the present embodiment, “to generate a new inorganic material by chemical reaction with each other by mechanical treatment” means that two or more kinds of coexisting inorganic compounds chemically react with each other by mechanical treatment to form a new inorganic material. It means that material is produced.

The inorganic composition can be obtained, for example, by mixing two or more inorganic compounds as raw materials at a predetermined molar ratio so that the inorganic material to be generated has a desired composition ratio.
The method of mixing two or more inorganic compounds is not particularly limited as long as each inorganic compound can be mixed uniformly. For example, a ball mill, a bead mill, a vibration mill, a blow mill, a mixer (pug mixer, ribbon mixer) Tumbler mixer, drum mixer, V-type mixer, etc.), kneader, biaxial kneader, airflow crusher, etc.
Mixing conditions such as agitation speed, processing time, temperature, reaction pressure, and gravitational acceleration applied to the mixture when mixing each inorganic compound can be appropriately determined depending on the amount of the mixture treated.

Although it does not specifically limit as an inorganic material to produce | generate, For example, an inorganic solid electrolyte material, a positive electrode active material, a negative electrode active material etc. are mentioned.
Although it does not specifically limit as an inorganic solid electrolyte material to produce | generate, A sulfide type inorganic solid electrolyte material, an oxide type inorganic solid electrolyte material, other lithium type inorganic solid electrolyte materials, etc. can be mentioned. Among these, sulfide-based inorganic solid electrolyte materials are preferable.
Moreover, it does not specifically limit as an inorganic solid electrolyte material to produce | generate, For example, what is used for the solid electrolyte layer which comprises an all-solid-type lithium ion battery is mentioned.

Examples of the sulfide-based inorganic solid electrolyte material to be generated include Li ₂ S—P ₂ S ₅ material, Li ₂ S—SiS ₂ material, Li ₂ S—GeS ₂ material, Li ₂ S—Al ₂ S ₃ material, _{Li 2 S-SiS 2 -Li 3} PO 4 _{material, Li 2 S-P 2 S} 5 -GeS 2 _{material, Li 2 S-Li 2 O} -P 2 S 5 -SiS 2 _material, Li ₂ S-GeS 2 - P ₂ S ₅ -SiS _{2 material, Li 2 S-SnS 2 -P} 2 S 5 -SiS 2 _{material, Li 2 S-P 2 S} 5 -Li 3 N _{materials, Li 2 S 2 + X -P} 4 S 3 material, _{li 2 S-P 2 S 5} -P 4 S 3 material, and the like.
Among these, Li ₂ S—P ₂ S ₅ material is preferable because it is excellent in lithium ion conductivity and has stability that does not cause decomposition in a wide voltage range. Here, for example, the Li ₂ S—P ₂ S ₅ material is an inorganic material obtained by chemically reacting an inorganic composition containing at least Li ₂ S (lithium sulfide) and P ₂ S ₅ with each other by mechanical treatment. Means material.
Here, in this embodiment, lithium polysulfide is also included in lithium sulfide.

Examples of the oxide-based inorganic solid electrolyte material include NASICON types such as LiTi ₂ (PO ₄ ) ₃ , LiZr ₂ (PO ₄ ) ₃ , LiGe ₂ (PO ₄ ) ₃ , and (La _{0.5 + x} Li _{0.5 −3x} ) TiO _{3 and} other perovskite types, Li ₂ O—P ₂ O ₅ materials, Li ₂ O—P ₂ O ₅ —Li ₃ N materials, and the like.
Examples of other lithium-based inorganic solid electrolyte materials include LiPON, LiNbO ₃ , LiTaO ₃ , Li ₃ PO ₄ , LiPO _4-x N _x (x is 0 <x ≦ 1), LiN, LiI, LISICON, and the like. It is done.
Furthermore, glass ceramics obtained by precipitating these inorganic solid electrolyte crystals can also be used as the inorganic solid electrolyte material.

  The sulfide-based inorganic solid electrolyte material according to this embodiment preferably includes Li, P, and S as constituent elements.

In the sulfide-based inorganic solid electrolyte material according to this embodiment, the molar ratio (Li / P) of the Li content to the P content in the solid electrolyte material is preferably 1.0 or more and 10. It is 0 or less, More preferably, it is 2.0 or more and 5.0 or less, More preferably, it is 3.0 or more and 4.5 or less, Especially preferably, it is 3.2 or more and 4.2 or less. Further, the molar ratio (S / P) of the content of S to the content of P is preferably 1.0 or more and 10.0 or less, more preferably 2.0 or more and 6.0 or less, Preferably they are 3.0 or more and 5.0 or less, Especially preferably, they are 3.2 or more and 4.5 or less.
Here, the contents of Li, P, and S in the solid electrolyte material of the present embodiment can be determined by, for example, ICP emission spectroscopic analysis or X-ray photoelectron spectroscopy.

Examples of the shape of the inorganic solid electrolyte material include particles. The particulate inorganic solid electrolyte material of the present embodiment is not particularly limited, but the average particle size d ₅₀ in the weight-based particle size distribution by the laser diffraction scattering type particle size distribution measurement method is preferably 1 μm or more and 40 μm or less, more preferably They are 2 micrometers or more and 30 micrometers or less, More preferably, they are 3 micrometers or more and 20 micrometers or less.
The average particle size d ₅₀ of the inorganic solid electrolyte material to be in the above range, while maintaining good handling properties, it is possible to further improve the lithium ion conductivity of the resulting solid electrolyte membrane.

It does not specifically limit as a positive electrode active material to produce | generate, For example, the positive electrode active material which can be used for the positive electrode layer of a lithium ion battery is mentioned. For example, lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), lithium manganese oxide (LiMn ₂ O ₄ ), solid solution oxide (Li ₂ MnO ₃ —LiMO ₂ (M = Co, Ni, etc.)) ), Lithium-manganese-nickel oxide (LiNi _1/3 Mn _1/3 Co _1/3 O ₂ ), olivine-type lithium phosphorus oxide (LiFePO ₄ ) and other complex oxides; CuS, Li—Cu—S compound Sulfide-based positive electrode active materials such as TiS ₂ , FeS, MoS ₂ , V ₂ S ₅ , Li—Mo—S compound, Li—Ti—S compound, Li—V—S compound, Li—Fe—S compound; Etc.
Among these, from the viewpoint of having a higher discharge capacity density and more excellent cycle characteristics, a sulfide-based positive electrode active material is preferable, and a Li—Mo—S compound, a Li—Ti—S compound, a Li—V—S is preferable. Compounds are more preferred.

Here, the Li—Mo—S compound contains Li, Mo, and S as constituent elements, and an inorganic composition containing molybdenum sulfide and lithium sulfide, which are usually raw materials, is chemically treated by mechanical treatment. It can be obtained by reacting.
Further, the Li—Ti—S compound contains Li, Ti, and S as constituent elements, and an inorganic composition containing titanium sulfide and lithium sulfide, which are usually raw materials, is chemically reacted with each other by mechanical treatment. Can be obtained.
The Li-VS compound contains Li, V, and S as constituent elements, and an inorganic composition containing vanadium sulfide and lithium sulfide, which are usually raw materials, is chemically reacted with each other by mechanical treatment. Can be obtained.

It does not specifically limit as a negative electrode active material to produce | generate, For example, the negative electrode active material which can be used for the negative electrode layer of a lithium ion battery is mentioned. For example, a metal material mainly composed of a lithium alloy, a tin alloy, a silicon alloy, a gallium alloy, an indium alloy, an aluminum alloy, or the like; a lithium titanium composite oxide (for example, Li ₄ Ti ₅ O ₁₂ ) or the like can be given.

(Step (B) of vitrifying the inorganic composition)
Next, the inorganic composition is vitrified while chemically reacting two or more kinds of the inorganic compounds by mechanically treating the inorganic composition using a pulverizer that combines shear stress and compressive stress.

  Here, the mechanical treatment is a method in which two or more inorganic compounds are mechanically collided to vitrify the inorganic composition while causing a chemical reaction. Can be mentioned. Here, the mechanochemical treatment is a method of vitrification while applying mechanical energy such as shearing force or collision force to the target composition.

  In the vitrification step (B), the mechanical treatment is preferably performed by a dry method. Thereby, the operation which removes liquid components, such as an organic solvent, from the vitrified inorganic composition becomes unnecessary, and productivity of an inorganic material can be improved more. Moreover, reaction with an inorganic material and an organic solvent can be prevented. Furthermore, since no liquid component such as an organic solvent is used, the safety in the manufacturing process can be further improved.

As a grinding device combining shear stress and compressive stress according to the present embodiment, for example, a roll mill; combining rotation (shear stress) and impact (compressive stress) represented by a rock drill, vibration drill, impact driver, and the like. Examples thereof include a rotation / blow pulverization apparatus comprising a mechanism; a high-pressure type grinding roll; and the like. Among these, a roll mill is preferable from the viewpoint of excellent continuous productivity.
Moreover, it is preferable that the roll mill which concerns on this embodiment is comprised by the 3 or more roll. Thereby, since vitrification processing can be performed more continuously, productivity of the obtained inorganic material can be further improved.
Moreover, it is preferable that the roll mill which concerns on this embodiment differs in the rotational speed of an adjacent roll. Thereby, since it can give a shear stress more effectively, giving a compressive stress with respect to the inorganic composition which exists between rolls, vitrification of an inorganic composition can be advanced still more efficiently.
Moreover, it is preferable that the roll mill which concerns on this embodiment differs in the direction which the adjacent roll rotates. Thereby, a compressive stress can be more effectively given with respect to the inorganic composition which exists between rolls.

It is preferable that at least the surface of the roll constituting the roll mill according to the present embodiment is made of at least one material selected from ceramic materials and metal materials.
Examples of the metal material include centrifugal chilled steel, SUS, Cr plated SUS, Cr plated hardened steel, and the like.
Moreover, when at least the surface of the roll constituting the roll mill according to the present embodiment is made of a ceramic material, it is possible to suppress the mixing of unnecessary metal components derived from the roll into the obtained inorganic material, and the purity. It is possible to obtain an inorganic material having a higher value.
Examples of such a ceramic material include zirconia, alumina, silicon carbide, silicon nitride, and the like.

FIG. 1 is a cross-sectional view showing an example of the structure of a crusher 100 according to an embodiment of the present invention. FIG. 1 shows an example of a three-roll mill in which the pulverizer 100 is composed of three rolls.
Hereinafter, the vitrification step (B) according to the present embodiment will be described more specifically with reference to FIG.
A pulverizing apparatus 100 illustrated in FIG. 1 includes a first roll 101, a second roll 102, a third roll 103, and a blade 130.
First, an inorganic composition 150 containing two or more kinds of inorganic compounds is charged into the first roll 110 between the first roll 101 and the second roll 102.
The inorganic composition 150 that has entered the space 110 between the first rolls is compressed by the first roll 101 and the second roll 102. Here, by adopting different rotation speeds in the first roll 101 and the second roll 102, the inorganic composition 150 that has entered between the first rolls 110 is more effectively applied with compressive stress. Since shear stress can be applied to the inorganic composition 150, vitrification of the inorganic composition 150 can be further efficiently performed.

  Here, it is preferable that the rotation speed of the roll is higher in the second roll 102 than in the first roll 101 and higher in the third roll 103 than in the second roll 102. That is, in the roll mill according to the present embodiment, the plurality of rolls are set so that the number of rotations gradually increases from the roll on the inorganic composition input side toward the roll on the inorganic material discharge side. It is preferable. The rotation speed of each roll is not particularly limited because it is appropriately determined depending on the number of rolls, the type of inorganic composition, the amount of treatment of the inorganic composition, and the like. In this case, when the speed of the first roll 101 is 1, the speed of the second roll 102 is 2 to 4, the speed of the third roll is 5 to 9, and the rotation is toward the discharged roll. You can speed up the number. By carrying out like this, the inorganic composition adhering to the roll can be more efficiently transferred to the surface of the adjacent roll, and as a result, the productivity of the inorganic material can be further improved.

Next, after passing the inorganic composition 150 between the first rolls 110, the inorganic composition 150 is passed between the second rolls 120 adjacent to the first rolls 110. Thereby, vitrification of the inorganic composition 150 can be performed continuously. Here, since the inorganic composition 150 adheres to the surface of the second roll 102 due to the compressive stress caused by the first roll 101 and the second roll 102, the inorganic composition 150 is continuously transferred between the second rolls 120. It is possible.
The inorganic material 170 obtained by passing between the second rolls 120 adheres to the surface of the third roll 103 and can be obtained by being scraped off by the blade 130, for example.
Moreover, about the inorganic material 170 obtained by passing between the 2nd roll 120, when vitrification is inadequate, the said process which passes 110 between 1st rolls and 120 between 2nd rolls is repeated. It is preferable. Alternatively, it is preferable that the number of rolls in the roll mill be four or more, and further mechanical treatment combining shear stress and compressive stress is performed.

Here, in the roll mill according to the present embodiment, the distance between the rolls is preferably 1 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less from the viewpoint of more effectively applying compressive stress to the inorganic composition.
Moreover, in the roll mill which concerns on this embodiment, from a viewpoint of giving a shear stress more effectively with respect to an inorganic composition, 20 rpm or more and 1000 rpm or less are preferable, and 100 rpm or more and 800 rpm or less are more preferable.
However, the distance between the rolls and the rotation speed of the rolls are not limited to the above ranges because they are appropriately determined according to the type and amount of the inorganic composition, the number of rolls and the like.

FIG. 2 is a cross-sectional view showing an example of the structure of the crusher 200 according to the embodiment of the present invention. FIG. 2 shows an example in which the crushing device 200 is a rotation / blow crushing device.
The crusher 200 shown in FIG. 2 includes, for example, an impact driver 201, a pestle 202, and a mortar 203. By using the impact driver 201, the pestle 202 repeatedly moves up and down, and compressive stress can be applied to the inorganic composition 250 existing in the mortar 203. Furthermore, by using the impact driver 201, the pestle 202 rotates and can apply a shear stress to the inorganic composition 250 existing in the mortar 203. From the above, it is possible to apply shear stress while applying compressive stress to the inorganic composition 250 existing in the mortar 203 by using the pulverizer 200 shown in FIG. Can proceed well.

Here, in the rotary / blow crushing apparatus according to the present embodiment, from the viewpoint of more effectively applying compressive stress to the inorganic composition, the number of hits is preferably 1 hit / min or more and 6200 hits / min or less, and 120 hits. More preferably, it is more than 500 hits / min and less than or equal to 5000 hits / min.
In addition, in the rotation / blow pulverization apparatus according to the present embodiment, the rotational speed of the pestle 202 is preferably 1 rpm or more and 5000 rpm or less, more preferably 60 rpm or more and 3500 rpm or less, from the viewpoint of more effectively applying shear stress to the inorganic composition. Preferably, 500 rpm or more and 3000 rpm is more preferable.
However, the number of hits and the number of revolutions are not limited to the above ranges because they are determined as appropriate depending on the type and processing amount of the inorganic composition, the size of the rotation / brush pulverization apparatus, and the like.

At least the surface of the pestle or mortar according to the present embodiment is preferably made of at least one material selected from ceramic materials and metal materials.
Examples of the metal material include centrifugal chilled steel, SUS, Cr plated SUS, Cr plated hardened steel, and the like.
In addition, when at least the surface of the pestle or mortar according to the present embodiment is made of a ceramic material, it is possible to suppress mixing of unnecessary metal components derived from the pestle or mortar into the obtained inorganic material, and purity. It is possible to obtain an inorganic material having a higher value.
Examples of such a ceramic material include zirconia, alumina, silicon carbide, silicon nitride, and the like.

The mechanochemical treatment is preferably performed in an inert atmosphere. Thereby, reaction with an inorganic composition, water vapor | steam, oxygen, etc. can be suppressed.
In addition, the inactive atmosphere is a vacuum atmosphere or an inert gas atmosphere. In the non-active atmosphere, the dew point is preferably −50 ° C. or lower, and more preferably −60 ° C. or lower in order to avoid contact with moisture. The “inert gas atmosphere” means an atmosphere of an inert gas such as argon gas, helium gas, nitrogen gas or the like. These inert gases are preferably as high as possible in order to prevent impurities from entering the product. The method of introducing the inert gas into the mixed system is not particularly limited as long as the mixed system is filled with an inert gas atmosphere. However, the inert gas is purged, and a constant amount of inert gas is continuously introduced. Methods and the like.

Mixing conditions such as a rotation speed, a treatment time, and a temperature when the inorganic composition is vitrified can be appropriately determined depending on the kind of inorganic composition and the amount of treatment. In general, the faster the rotation speed, the faster the glass production rate, and the longer the treatment time, the higher the conversion to glass.
Usually, when X-ray diffraction analysis using CuKα rays as a radiation source is performed, if the diffraction peak of the inorganic composition disappears or decreases, the inorganic composition is vitrified to obtain a desired inorganic material. Can be determined.

Here, when the inorganic material to be generated is a sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements, in the step (B) of vitrifying the inorganic composition, CuKα rays are used as a radiation source. and background intensity I _a of the diffraction intensity of the diffraction peak at the position of the diffraction angle 2θ = 15.7 ± 0.3 ° in the spectrum obtained by X-ray diffraction using the diffraction angle 2 [Theta] = 26.9 ± 0 when the diffraction intensity of the diffraction peak at the position of .9 ° was _{I B,} the value of I B / _{I a} is preferably 5.5 or less, more preferably 4.0 or less, more preferably 3.0 or less It is preferable to perform mechanical treatment until
The I B _/ I _A With more than the above upper limit, it is possible to improve the lithium ion conductive sulfide-based inorganic solid electrolyte material. Further, when such a sulfide-based inorganic solid electrolyte material is used, an all solid-state lithium ion battery having excellent input / output characteristics can be obtained.
Here, the diffraction peak existing at the position of diffraction angle 2θ = 15.7 ± 0.3 ° is the reference diffraction peak, and the diffraction peak existing at the position of diffraction angle 2θ = 26.9 ± 0.9 °. Is a diffraction peak derived from lithium sulfide.
Therefore, I B _/ I _A represents an indication of the content of lithium sulfide in the sulfide-based inorganic solid electrolyte material during. It means that the smaller I _B / I _A is, the smaller the amount of lithium sulfide contained in the sulfide-based inorganic solid electrolyte material.
Since Li ₂ S has low lithium ion conductivity, it is considered that the lithium ion conductivity of the sulfide-based inorganic solid electrolyte material improves as the content of Li ₂ S decreases.

When the inorganic material to be generated is a sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements, in the step (B) of vitrifying the inorganic composition, 27.0 ° C. is applied. The lithium ion conductivity by the AC impedance method under measurement conditions of a voltage of 10 mV and a measurement frequency range of 0.1 Hz to 7 MHz is preferably 2.0 × 10 ⁻⁵ S · cm ⁻¹ or more, more preferably 1.0 × 10 ^−4. It is preferable to perform mechanical treatment until S · cm ⁻¹ or more. Thereby, the sulfide type inorganic solid electrolyte material which was further excellent by lithium ion conductivity can be obtained.

(Crystalling step (C) for crystallizing the inorganic composition)
In the manufacturing method of the inorganic material which concerns on this embodiment, an inorganic composition is crystallized by heating the said inorganic composition prepared at the process (A) between a preparatory process (A) and the vitrification process (B). It is preferable to further perform the step of converting.
That is, it is preferable to perform the vitrification step (B) on the crystallized inorganic composition.
By performing the crystallization step (C) before the vitrification step (B), the step (B) of vitrifying the inorganic composition can be greatly shortened, and as a result, the production time of the inorganic material can be reduced. Further shortening is possible. The reason for this is not clear, but the following reason is presumed.
First, a glassy inorganic composition is in a metastable state. On the other hand, the inorganic composition in the crystalline state is in a stable state. In addition, when an inorganic composition containing two or more inorganic compounds is heated, energy higher than the activation energy can be easily given, so that the crystalline inorganic composition which is in a low energy state can be quickly released along with the release of energy. can get. And since the free energy of a stable state and the free energy of a metastable state are near, it can change from the crystal state of a stable state to the glass state of a metastable state with smaller energy.
For the above reasons, by performing the step (C) of crystallizing the inorganic composition before the step (B) of vitrifying the inorganic composition, the inorganic composition is made into a stable crystalline state in advance. It can be considered that the metastable glass state can be obtained with smaller energy, and the process of vitrifying the inorganic composition can be greatly shortened.

It does not specifically limit as temperature at the time of heating the said inorganic composition, According to the inorganic material to produce | generate, it can set suitably.
For example, when the inorganic material to be generated is a sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements, the heating temperature is preferably in the range of 200 ° C. to 400 ° C., and 220 ° C. More preferably, it is in the range of 300 ° C. or less.

  The time for heating the inorganic composition is not particularly limited as long as the inorganic composition can be crystallized. For example, the time is within a range of 1 minute to 24 hours, preferably 0.1 It is more than time and less than 10 hours. The heating method is not particularly limited, and examples thereof include a method using a firing furnace. In addition, conditions, such as temperature and time at the time of such a heating, can be suitably adjusted in order to optimize the characteristic of the inorganic material of this embodiment.

  Whether or not the inorganic composition has been crystallized can be determined, for example, based on whether or not a new crystal peak has been generated in a spectrum obtained by X-ray diffraction using CuKα rays as a radiation source.

(Step (D) of crystallizing at least a part of the inorganic composition)
Subsequently, by heating the obtained inorganic material in the glass state, at least a part of the inorganic material may be crystallized to generate an inorganic material in the glass ceramic state. By carrying out like this, the inorganic solid electrolyte material which was further excellent in lithium ion conductivity can be obtained, for example.

The temperature at which the glassy inorganic material is heated is preferably in the range of 200 ° C. or higher and 500 ° C. or lower, and more preferably in the range of 220 ° C. or higher and 350 ° C. or lower.
The time for heating the inorganic material in the glass state is not particularly limited as long as the desired inorganic material can be obtained. For example, the time is within a range of 1 minute to 24 hours, preferably 0.5. More than 3 hours. The heating method is not particularly limited, and examples thereof include a method using a firing furnace. In addition, conditions, such as temperature and time at the time of such a heating, can be suitably adjusted in order to optimize the characteristic of the inorganic material of this embodiment.

Moreover, it is preferable to perform the heating of the inorganic material in a glass state in, for example, an inert gas atmosphere. Thereby, deterioration (for example, oxidation) of an inorganic material can be prevented.
Examples of the inert gas when heating the inorganic material in the glass state include argon gas, helium gas, nitrogen gas, and the like. These inert gases are preferably higher in purity in order to prevent impurities from entering the product, and in order to avoid contact with moisture, the dew point is preferably −50 ° C. or lower, and −60 It is particularly preferable that the temperature is not higher than ° C. The method of introducing the inert gas into the mixed system is not particularly limited as long as the mixed system is filled with an inert gas atmosphere. However, the inert gas is purged, and a constant amount of inert gas is continuously introduced. Methods and the like.

(Step of grinding, classifying or granulating (E))
In the manufacturing method of the inorganic material of this embodiment, you may further perform the process of grind | pulverizing, classifying, or granulating the obtained inorganic material as needed. For example, an inorganic material having a desired particle diameter can be obtained by making fine particles by pulverization and then adjusting the particle diameter by classification operation or granulation operation. It does not specifically limit as said grinding | pulverization method, Well-known grinding | pulverization methods, such as a mixer, airflow grinding | pulverization, a mortar, a rotary mill, a coffee mill, can be used. Moreover, it does not specifically limit as said classification method, Well-known methods, such as a sieve, can be used.
These pulverization or classification are preferably performed in an inert gas atmosphere or a vacuum atmosphere from the viewpoint that contact with moisture in the air can be prevented.

As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable.
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to these.

<Evaluation method>
First, evaluation methods in the following examples and comparative examples will be described.

(1) X-ray diffraction analysis Diffraction spectra of the inorganic solid electrolyte materials obtained in Examples and Comparative Examples were determined by X-ray diffraction analysis using an X-ray diffraction apparatus (RINT2000, manufactured by Rigaku Corporation). Note that CuKα rays were used as the radiation source. Here, the diffraction intensity of the diffraction peak at the position of the diffraction angle 2θ = 15.7 ± 0.3 ° and background intensity _{I A,} at the position of the diffraction angle 2θ = 26.9 ± 0.9 ° the diffraction intensity of the diffraction peak was determined as the _{I B I B} / _{I a.}

(2) Measurement of lithium ion conductivity Lithium ion conductivity was measured by the AC impedance method for the solid electrolyte materials obtained in the examples and comparative examples.
Lithium ion conductivity was measured using a potentiostat / galvanostat SP-300 manufactured by Hokuto Denko Corporation. The size of the sample was φ9.5 mm, the thickness was about 1.3 mm, the measurement conditions were an applied voltage of 10 mV, a measurement temperature of 27.0 ° C., a measurement frequency range of 0.1 Hz to 7 MHz, and the electrode was a Li foil.

<Example 1>
The Li 2 _{S-P 2} S ₅ material is a sulfide-based inorganic solid electrolyte material was prepared by the following procedure.
Li ₂ S (manufactured by Sigma-Aldrich Japan, purity 99.9%) and P ₂ S ₅ (reagent made by Kanto Chemical) were used as raw materials.
A total of 30 g of Li ₂ S powder and P ₂ S ₅ powder (Li ₂ S: P ₂ S ₅ = 80: 20 (mol%)) was mixed for 1 hour at 120 rpm in a ball mill (400 mL pot, φ10 mm ball 500 g used). .
Next, 5.0 g of the obtained mixture (inorganic composition) was put in an alumina crucible and heated in a heating furnace in a glove box at 300 ° C. for 1 hour to crystallize the inorganic composition.
Next, 2.5 g of the crystallized inorganic composition was mechanochemically treated with a three-roll mill (BR-100V manufactured by Imex Co., Ltd.) shown in FIG. 1 to obtain a sulfide-based inorganic solid electrolyte material. Here, the first roll 101 to the third roll 103 were passed once, and were passed 100 times in total. Each roll was made of zirconia (ZrO ₂ ) and had a diameter of 38 mm, and the distance between the rolls was 20 μm. Also, the rotation speed of the first roll 101: the rotation speed of the second roll 102: the rotation speed of the third roll 103 = 1: 2.5: 6, and the rotation speed of the third roll 103 was 700 rpm. .

After passing through the first roll 101 to the third roll 103 20 times and after 100 times, a part of the sample was sampled, and each physical property was evaluated.
Lithium ion conductivity of mechanochemical pretreatment of crystallized inorganic composition is ^{1.1 × 10 -5 S · cm -1} , the value of I B / _{I A} was 5.6.
The lithium ion conductivity of the sulfide-based inorganic solid electrolyte material after passing through the first roll 101 to the third roll 103 20 times is 4.8 × 10 ⁻⁵ S · cm ⁻¹ , and I _B / value of _{I a} was 3.4.
Further, the lithium ion conductivity of the sulfide-based inorganic solid electrolyte material after passing through the first roll 101 to the third roll 103 100 times is 2.0 × 10 ⁻⁴ S · cm ⁻¹ , The value of I _B / I _A was 2.0.
The production method of Example 1 does not require an operation of scraping off the inorganic composition from the wall surface in the container in the course of the production process, an operation of separating the vitrified inorganic composition from a ball mill, a bead mill, or the like. Mechanical processing was possible. It and the improvement of lithium ion conductivity is observed, since the value of I B _/ I _A is reduced, the progress of the vitrification was observed.

<Example 2>
The Li 2 _{S-P 2} S ₅ material is a sulfide-based inorganic solid electrolyte material was prepared by the following procedure.
Li ₂ S (manufactured by Sigma-Aldrich Japan, purity 99.9%) and P ₂ S ₅ (reagent made by Kanto Chemical) were used as raw materials.
A total of 30 g of Li ₂ S powder and P ₂ S ₅ powder (Li ₂ S: P ₂ S ₅ = 80: 20 (mol%)) was mixed for 1 hour at 120 rpm in a ball mill (400 mL pot, φ10 mm ball 500 g used). .
Next, 5.0 g of the obtained mixture (inorganic composition) was placed in an alumina crucible and heated in a heating furnace in a glove box at 240 ° C. for 1 hour to crystallize the inorganic composition.
Next, 2.5 g of the crystallized inorganic composition was subjected to mechanochemical treatment for 120 minutes using a rotary / blow pulverizer shown in FIG. 2 to obtain a sulfide-based inorganic solid electrolyte material. Here, as the impact driver 201, one having a mass of 0.58 kg and a maximum rotational torque of 25 N · m was used, and the mechanochemical treatment was performed under the conditions of the rotational speed: 2400 rpm and the impact number: 3000 impacts / minute. The pestle 202 was made of alumina and had a diameter of 25 mm and a mass of 0.63 kg. The mortar 203 was an alumina mortar.

The mechanochemical treatment was performed for a total of 120 minutes, and a part of the sample was sampled after 15 minutes and 120 minutes, and each physical property was evaluated.
Lithium ion conductivity of mechanochemical pretreatment of crystallized inorganic composition is ^{1.2 × 10 -6 S · cm -1} , the value of I B / _{I A} is in was 5.6.
Lithium ion conductivity of the sulfide-based inorganic solid electrolyte material 15 minutes after mechanochemical treatment initiation is ^{1.4 × 10 -5 S · cm -1} , the value of I B / _{I A} is in 4.7 there It was.
Further, the lithium ion conductivity of the sulfide-based inorganic solid electrolyte material of 120 minutes after the mechanochemical treatment initiation is ^{2.0 × 10 -4 S · cm -1} , the value of I B / _{I A} 2.4 Met.
The production method of Example 2 does not require an operation of scraping off the inorganic composition from the wall surface in the container in the course of the production process, an operation of separating the vitrified inorganic composition from a ball mill or a bead mill, and the like. Mechanical processing was possible. It and the improvement of lithium ion conductivity is observed, since the value of I B _/ I _A is reduced, the progress of the vitrification was observed.

<Comparative Example 1>
The Li 2 _{S-P 2} S ₅ material is a sulfide-based inorganic solid electrolyte material was prepared by the following procedure.
Li ₂ S (manufactured by Sigma-Aldrich Japan, purity 99.9%) and P ₂ S ₅ (reagent made by Kanto Chemical) were used as raw materials.
A total of 30 g of Li ₂ S powder and P ₂ S ₅ powder (Li ₂ S: P ₂ S ₅ = 80: 20 (mol%)) was mixed for 1 hour at 120 rpm in a ball mill (400 mL pot, φ10 mm ball 500 g used). .
Next, 5.0 g of the obtained mixture (inorganic composition) was put in an alumina crucible and heated in a heating furnace in a glove box at 300 ° C. for 1 hour to crystallize the inorganic composition.
Next, 2.5 g of the crystallized inorganic composition was mechanochemically treated at 120 rpm for 24 hours in a ball mill (400 mL pot, φ10 mm ball 500 g used). Subsequently, the obtained sulfide-based inorganic solid electrolyte material was separated from a φ10 mm ball to obtain a sulfide-based inorganic solid electrolyte material.
Here, when the 400 mL pot was opened after 24 hours of mechanochemical treatment, a lump of the inorganic composition was adhered to the inner wall of the 400 mL pot. Therefore, it was necessary to scrape off the mass of the inorganic composition adhering to the inner wall of the pot every 4 hours.

Lithium ion conductivity of mechanochemical pretreatment of crystallized inorganic composition is ^{1.1 × 10 -5 S · cm -1} , the value of I B / _{I A} was 5.7.
Lithium ion conductivity of the sulfide-based inorganic solid electrolyte material after mechanochemical treatment is ^{2.0 × 10 -4 S · cm -1} , the value of I B / _{I A} was 2.6.

  From the above, the manufacturing method of the inorganic material of Examples 1 and 2 using the pulverizing apparatus combining the shear stress and the compressive stress does not require the use of a ball mill or a bead mill, and the inorganic composition from the wall surface in the container during the manufacturing process. It was found that an operation of scraping off an object and an operation of separating a vitrified inorganic composition from a ball mill, a bead mill or the like are unnecessary, and a continuous vitrification treatment is possible. On the other hand, in the manufacturing method of the inorganic material of the comparative example 1 using the ball mill, the operation of scraping off the inorganic composition from the wall surface in the container during the manufacturing process, or the operation of separating the vitrified inorganic composition from the ball mill Was necessary, and continuous productivity was inferior.

DESCRIPTION OF SYMBOLS 100 Crusher 101 1st roll 102 2nd roll 103 3rd roll 110 Between 1st rolls 120 Between 2nd rolls 130 Blade 150 Inorganic composition 170 Inorganic material 200 Crusher 201 Impact driver 202 Pestle 203 Mortar 250 Inorganic composition

Claims (16)

A production method for producing an inorganic material obtained by chemically reacting two or more kinds of inorganic compounds by mechanical treatment,
A preparation step of preparing an inorganic composition containing two or more inorganic compounds;
A vitrification step of vitrifying the inorganic composition while chemically reacting two or more of the inorganic compounds by mechanically treating the inorganic composition using a pulverizing apparatus that combines shear stress and compressive stress. ,
The manufacturing method of the inorganic material containing this. In the manufacturing method of the inorganic material of Claim 1,
The said mechanical treatment in the said vitrification process is a manufacturing method of the inorganic material performed by a dry type. In the manufacturing method of the inorganic material of Claim 1 or 2,
The manufacturing method of the inorganic material in which the said grinding | pulverization apparatus which combined the shear stress and the compressive stress contains at least one selected from a roll mill, a rotation and impact grinding | pulverization apparatus, and a high-pressure type grinding roll. In the manufacturing method of the inorganic material of Claim 3,
The grinding device includes a roll mill;
The manufacturing method of the inorganic material in which the said roll mill is comprised by the 3 or more roll. In the manufacturing method of the inorganic material of Claim 3 or 4,
The roll mill is a method for producing an inorganic material in which adjacent rolls have different rotational speeds. In the manufacturing method of the inorganic material as described in any one of Claims 3 thru | or 5,
In the vitrification step, after the inorganic composition is passed between the first rolls in the roll mill, the inorganic composition is passed between the second rolls adjacent to the first rolls. Production method. In the manufacturing method of the inorganic material as described in any one of Claims 3 thru | or 6,
A method for producing an inorganic material, wherein at least a surface of a roll constituting the roll mill is made of at least one material selected from a ceramic material and a metal material. In the manufacturing method of the inorganic material as described in any one of Claims 1 thru | or 7,
The manufacturing method of the inorganic material which further performs the process of crystallizing the said inorganic composition by heating the said inorganic composition between the said preparatory process and the said vitrification process. In the manufacturing method of the inorganic material as described in any one of Claims 1 thru | or 8,
The mechanical treatment is a method for producing an inorganic material including a mechanochemical treatment. In the manufacturing method of the inorganic material as described in any one of Claims 1 thru | or 9,
A method for producing an inorganic material, wherein the inorganic material is an inorganic solid electrolyte material, a positive electrode active material, or a negative electrode active material. In the manufacturing method of the inorganic material of Claim 10,
A method for producing an inorganic material, wherein the inorganic material is an inorganic solid electrolyte material used for a solid electrolyte layer constituting an all-solid-state lithium ion battery. In the manufacturing method of the inorganic material of Claim 10 or 11,
The inorganic material is an inorganic solid electrolyte material;
A method for producing an inorganic material, wherein the inorganic solid electrolyte material includes a sulfide-based inorganic solid electrolyte material. In the manufacturing method of the inorganic material of Claim 12,
The said sulfide type inorganic solid electrolyte material is a manufacturing method of the inorganic material which contains Li, P, and S as a structural element. In the manufacturing method of the inorganic material of Claim 13,
The molar ratio (Li / P) of the Li content to the P content in the sulfide-based inorganic solid electrolyte material is 1.0 or more and 10.0 or less, and the S content relative to the P content The manufacturing method of the inorganic material whose molar ratio (S / P) of content is 1.0 or more and 10.0 or less. In the manufacturing method of the inorganic material of Claim 13 or 14,
In the step of vitrifying the inorganic composition,
The diffraction intensity of the diffraction peak at the position of the diffraction angle 2θ = 15.7 ± 0.3 ° in the spectrum obtained by X-ray diffraction using a CuKα ray as a radiation source and background intensity I _A, a diffraction angle 2 [Theta] = the diffraction intensity of the diffraction peak at the position of 26.9 ± 0.9 ° when the I _B, the production of inorganic materials to perform the mechanical processing until the value of I B _/ I _a is 5.5 or less Method. In the manufacturing method of the inorganic material as described in any one of Claims 13 thru | or 15,
The lithium ion conductivity of the inorganic material is 2.0 × 10 ⁻⁵ S · cm ⁻¹ or more according to an 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. Inorganic material manufacturing method.

Images