JP2023063326A - Sulfide based inorganic solid electrolyte material, solid electrolyte, solid electrolyte membrane and lithium ion battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sulfide based inorganic solid electrolyte material capable of suppressing the reduction of lithium ion conductivity during exposure in the atmosphere.

SOLUTION: The sulfide based inorganic solid electrolyte material has lithium ion conductivity and includes Li, P and S as a constituent element, and the generation rate of hydrogen sulfide measured by the following method is 20 ppm or less. The method comprises: arranging the sulfide based inorganic solid electrolyte material in a glass closed vessel replaced with argon gas; and measuring the amount of hydrogen sulfide gas generated in the glass closed vessel after 5 minutes from the drop of water into the sulfide based inorganic solid electrolyte material from the upper portion of the glass closed vessel.

SELECTED DRAWING: None

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a sulfide-based inorganic solid electrolyte material, a solid electrolyte, a solid electrolyte membrane, and a lithium ion battery.

Lithium ion batteries are generally used as power sources for small portable devices such as mobile phones and laptop computers. In addition to small portable devices, recently, lithium ion batteries have begun to be used as power sources for electric vehicles, power storage, and the like.

Lithium-ion batteries currently on the market use electrolytes containing flammable organic solvents. On the other hand, a lithium-ion battery in which the electrolytic solution is changed to a solid electrolyte to make the battery completely solid (hereinafter also referred to as an all-solid-state lithium-ion battery) does not use a flammable organic solvent in the battery, so it is a safety device. simplification, and it is considered to be excellent in manufacturing cost and productivity.

As a solid electrolyte material used for such a solid electrolyte, for example, a sulfide-based inorganic solid electrolyte material is known.

Patent Document 1 (Japanese Patent Application 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 (0 .1≦y≦0.175).

JP 2016-27545 A

According to the studies of the present inventors, it has become clear that the lithium ion conductivity of the sulfide-based inorganic solid electrolyte material may gradually decrease when exposed to the atmosphere.
In other words, conventional sulfide-based inorganic solid electrolyte materials have room for improvement in terms of suppressing deterioration in lithium ion conductivity when exposed to the atmosphere.

The present invention has been made in view of the above circumstances, and provides a sulfide-based inorganic solid electrolyte material capable of suppressing a decrease in lithium ion conductivity when exposed to the atmosphere.

The present inventors have made intensive studies to provide a sulfide-based inorganic solid electrolyte material that can suppress a decrease in lithium ion conductivity when exposed to the air. As a result, the present inventors have found that a sulfide-based inorganic solid electrolyte material that generates a small amount of hydrogen sulfide as measured by a specific method can suppress a decrease in lithium ion conductivity when exposed to the atmosphere, leading to the present invention. .

That is, according to the present invention,
A sulfide-based inorganic solid electrolyte material having lithium ion conductivity and containing Li, P and S as constituent elements,
Provided is a sulfide-based inorganic solid electrolyte material that generates 20 ppm or less of hydrogen sulfide, as measured by the following method.
(Method)
The sulfide-based inorganic solid electrolyte material is placed in a closed glass container that has been replaced with argon gas, and then water is added dropwise from the top of the closed glass container to the sulfide-based inorganic solid electrolyte material for 5 minutes. Afterwards, the amount of hydrogen sulfide gas generated in the closed glass container is measured.

Moreover, according to the present invention,
A solid electrolyte containing the sulfide-based inorganic solid electrolyte material is provided.

Furthermore, according to the present invention,
A solid electrolyte membrane containing the solid electrolyte as a main component is provided.

Furthermore, according to the present invention,
A lithium ion battery comprising a positive electrode including a positive electrode active material layer, an electrolyte layer, and a negative electrode including a negative electrode active material layer,
At least one of the positive electrode active material layer, the electrolyte layer, and the negative electrode active material layer contains the sulfide-based inorganic solid electrolyte material.

According to the present invention, it is possible to provide a sulfide-based inorganic solid electrolyte material capable of suppressing a decrease in lithium ion conductivity when exposed to the atmosphere.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of the structure of the lithium ion battery of embodiment which concerns on this invention. FIG. 2 shows X-ray diffraction spectra of sulfide-based inorganic solid electrolyte materials obtained in Examples. FIG. 2 is a diagram showing an X-ray diffraction spectrum of a sulfide-based inorganic solid electrolyte material obtained in a comparative example; FIG. 2 is a photograph showing an apparatus used for measuring the amount of hydrogen sulfide generated from sulfide-based inorganic solid electrolyte materials obtained in Examples and Comparative Examples.

An embodiment of the present invention will be described below with reference to the drawings. In addition, in all the drawings, the same constituent elements are denoted by the same reference numerals, and the explanation thereof is omitted as appropriate. Also, the drawings are schematic diagrams and do not correspond to actual dimensional ratios. The numerical range "A to B" represents from A to B unless otherwise specified.

[Sulfide-based inorganic solid electrolyte material]
First, the sulfide-based inorganic solid electrolyte material according to this embodiment will be described.
The sulfide-based inorganic solid electrolyte material according to the present embodiment is a sulfide-based inorganic solid electrolyte material that has lithium ion conductivity and contains Li, P, and S as constituent elements, and is measured by the following method. The amount of hydrogen sulfide generated is 20 ppm or less, preferably 15 ppm or less, more preferably 10 ppm or less. Although the lower limit of the amount of hydrogen sulfide generated is not particularly limited, it is, for example, 1 ppm or more, preferably 0.1 ppm or more.
(Method)
The sulfide-based inorganic solid electrolyte material is placed in a closed glass container that has been replaced with argon gas, and then water is added dropwise from the top of the closed glass container to the sulfide-based inorganic solid electrolyte material for 5 minutes. Afterwards, the amount of hydrogen sulfide gas generated in the closed glass container is measured.

In the sulfide-based inorganic solid electrolyte material according to the present embodiment, the amount of hydrogen sulfide generated measured by the above method is equal to or less than the above upper limit value, so that lithium ion conductivity decreases when exposed to the atmosphere. can be suppressed. Furthermore, lithium ion conductivity can be improved by setting the amount of hydrogen sulfide generated to be equal to or less than the above upper limit.
Although the reason for this is not necessarily clear, the following reasons are presumed.
This is probably because a sulfide-based inorganic solid electrolyte material that generates hydrogen sulfide in an amount equal to or less than the upper limit has a structure that does not readily react with moisture contained in the air.
Therefore, the fact that the amount of hydrogen sulfide generated measured by the above method is equal to or less than the above upper limit indicates that a novel structure different from conventional typical sulfide-based inorganic solid electrolyte materials is formed. is thought to represent
In the present embodiment, the sulfide-based inorganic solid electrolyte material in which the amount of hydrogen sulfide generated is the above upper limit or less is obtained by highly controlling the composition ratio of the sulfide-based inorganic solid electrolyte material and by combining shear stress and compressive stress. Using a pulverizing device, the process of vitrifying and annealing the raw material inorganic composition is continuously performed, and stronger shearing force and compressive force than before are applied to produce a sulfide-based inorganic solid electrolyte material. It can be realized by manufacturing or the like.

The sulfide-based inorganic solid electrolyte material according to the present embodiment has a diffraction angle 2θ = 17.2 ± 0.5 ° in a spectrum obtained by X-ray diffraction using CuKα rays as a radiation source, a diffraction angle 2θ = 25 It is preferable to have diffraction peaks at a position of 0.6±0.5° and a position of diffraction angle 2θ=29.2±0.8°.
This makes it possible to improve the lithium ion conductivity while maintaining good electrochemical stability.

The sulfide-based inorganic solid electrolyte material according to the present embodiment has the maximum diffraction intensity at the diffraction angle 2θ = 35.0 ± 0.1 ° in the spectrum obtained by X-ray diffraction using CuKα rays as a radiation source. When the ground intensity is I _A and the maximum diffraction intensity of the diffraction peak present at the diffraction angle 2θ=17.2±0.5° is I _B , the value of I _B / _IA is preferably 2.0 or more. , more preferably 3.5 or more, still more preferably 5.0 or more, and particularly preferably 6.0 or more.
Lithium ion conductivity can be further improved by setting the value of _IB / _IA to the above lower limit or more.
In addition, in the sulfide-based inorganic solid electrolyte material according to the present embodiment, the upper limit of the value of I _B /I _A is not particularly limited, but is, for example, 30.0 or less, preferably 20.0 or less, more preferably 15.0. It is 0 or less, particularly preferably 13.0 or less.
The value of I _B / _IA of the sulfide-based inorganic solid electrolyte material according to the present embodiment can be adjusted by adjusting the composition ratio of the sulfide-based inorganic solid electrolyte material or by vitrifying the raw material inorganic composition. It is possible to realize the step of performing the annealing treatment continuously by using a pulverizing device that combines shear stress and compressive stress.

The sulfide-based inorganic solid electrolyte material according to the present embodiment has the maximum diffraction intensity at the diffraction angle 2θ = 35.0 ± 0.1 ° in the spectrum obtained by X-ray diffraction using CuKα rays as a radiation source. When the ground intensity is I _A and the maximum diffraction intensity of the diffraction peak present at the diffraction angle 2θ=25.6±0.5° is I _C , the value of I _C / _IA is preferably 2.0 or more. , more preferably 2.5 or more, and still more preferably 3.0 or more.
In addition, in the sulfide-based inorganic solid electrolyte material according to the present embodiment, the upper limit of the value of I _C /I _A is not particularly limited. It is 0 or less, particularly preferably 8.0 or less.
The I _C /I _A value of the sulfide-based inorganic solid electrolyte material according to this embodiment can be achieved by adjusting the composition ratio of the sulfide-based inorganic solid electrolyte material.

The sulfide-based inorganic solid electrolyte material according to the present embodiment has the maximum diffraction intensity at the diffraction angle 2θ = 35.0 ± 0.1 ° in the spectrum obtained by X-ray diffraction using CuKα rays as a radiation source. When the ground intensity is I _A and the maximum diffraction intensity of the diffraction peak present at the diffraction angle 2θ=29.2±0.8° is I _D , the value of I _D /I _A is preferably 2.0 or more. , more preferably 3.0 or more, still more preferably 4.0 or more, and particularly preferably 5.0 or more.
In addition, in the sulfide-based inorganic solid electrolyte material according to the present embodiment, the upper limit of the value of I _D /I _A is not particularly limited. It is 0 or less, particularly preferably 10.5 or less.
The I _D /I _A value of the sulfide-based inorganic solid electrolyte material according to the present embodiment can be achieved by adjusting the composition ratio of the sulfide-based inorganic solid electrolyte material.

In addition, the sulfide-based inorganic solid electrolyte material according to the present embodiment further has a diffraction peak at a diffraction angle 2θ = 26.6 ± 0.4 ° in a spectrum obtained by X-ray diffraction using CuKα rays as a radiation source. It is preferred to have
This makes it possible to further improve the lithium ion conductivity while maintaining good electrochemical stability.
Although the reason for this is not necessarily clear, the following reasons are presumed.
A sulfide-based inorganic solid electrolyte material that further has a diffraction peak at _a diffraction angle of 2θ=26.6±0.4° is significantly different from typical conventional sulfide-based inorganic solid electrolyte materials such as _Li3PS4 . It shows different X-ray diffraction profiles (see JCPDS (Joint Committee on Powder Diffraction Standards) card No. 01-076-0973, which is an XRD database of Li ₃ PS ₄ ).
Therefore, a sulfide-based inorganic solid electrolyte material having a diffraction peak at a diffraction angle of 2θ=26.6±0.4° has a novel structure different from conventional sulfide-based inorganic solid electrolyte materials. It is thought that there are It is believed that such a novel structure is one in which lithium ions hop more easily. Therefore, the sulfide-based inorganic solid electrolyte material according to the present embodiment has excellent lithium ion diffusibility, and as a result, exhibits higher ionic conductivity than typical conventional sulfide-based inorganic solid electrolyte materials. it is conceivable that.
Therefore, the diffraction angle 2θ=17.2±0.5°, the diffraction angle 2θ=25.6±0.5°, the diffraction angle 2θ=26.6±0.4° and the diffraction angle 2θ=29 Having diffraction peaks at the positions of 0.2±0.8° is considered to represent the formation of a novel structure different from conventional typical sulfide-based inorganic solid electrolyte materials.
The X-ray diffraction profile of the sulfide-based inorganic solid electrolyte material according to the present embodiment can be obtained by adjusting the composition ratio of the sulfide-based inorganic solid electrolyte material, vitrifying the raw material inorganic composition, and annealing. It is possible to realize the step of continuously performing, for example, using a pulverizer that combines shear stress and compressive stress.

The sulfide-based inorganic solid electrolyte material according to the present embodiment has the maximum diffraction intensity at the diffraction angle 2θ = 35.0 ± 0.1 ° in the spectrum obtained by X-ray diffraction using CuKα rays as a radiation source. When the ground intensity is I _A and the maximum diffraction intensity of the diffraction peak present at the diffraction angle 2θ=26.6±0.4° is I _E , the value of I _E / _IA is preferably 2.2 or more. , more preferably 2.5 or more, still more preferably 3.0 or more, and particularly preferably 3.5 or more.
By making the value of I _E / _IA equal to or higher than the above lower limit, the lithium ion conductivity can be further improved.
In addition, in the sulfide-based inorganic solid electrolyte material according to the present embodiment, the upper limit of the value of I _E /I _A is not particularly limited, but is, for example, 15.0 or less, preferably 10.0 or less, more preferably 8.0. 0 or less, more preferably 6.5 or less, and particularly preferably 5.0 or less.
The I _E / _IA value of the sulfide-based inorganic solid electrolyte material according to this embodiment can be achieved by adjusting the composition ratio of the sulfide-based inorganic solid electrolyte material.

The sulfide-based inorganic solid electrolyte material according to the present embodiment is a sulfide-based inorganic solid electrolyte material from the viewpoint of further improving lithium ion conductivity, electrochemical stability, stability in moisture and air, handleability, etc. The molar ratio Li/P of the content of Li to the content of P in the solid electrolyte material is preferably 1.0 or more and 5.0 or less, more preferably 2.0 or more and 4.0 or less, It is more preferably 2.5 or more and 3.8 or less, still more preferably 2.8 or more and 3.6 or less, still more preferably 3.0 or more and 3.5 or less, and still more preferably 3.0 or more. 1 or more and 3.4 or less, particularly preferably 3.1 or more and 3.3 or less, and the molar ratio S/P of the S content to the P content is preferably 2.0 or more and 6.0 or less, more preferably 3.0 or more and 5.0 or less, still more preferably 3.5 or more and 4.5 or less, still more preferably 3.8 or more and 4.2 or less, still more preferably 3 0.9 or more and 4.1 or less, particularly preferably 4.0.
Here, the contents of Li, P and S in the sulfide-based inorganic solid electrolyte material according to the present embodiment can be determined by, for example, ICP emission spectroscopic analysis or X-ray analysis.

In the sulfide-based inorganic solid electrolyte material according to this embodiment, the lithium ion conduction of the sulfide-based inorganic solid electrolyte material by the AC impedance method under the measurement conditions of 27.0 ° C., an applied voltage of 10 mV, and a measurement frequency range of 0.1 Hz to 7 MHz. The degree is preferably 2.2×10 ⁻⁴ S·cm ⁻¹ or more, more preferably 3.0×10 ⁻⁴ S·cm ⁻¹ or more, and still more preferably 4.0×10 ⁻⁴ S·cm −1 or more ^{. 1} or more, particularly preferably 5.0×10 ⁻⁴ S·cm ⁻¹ or more.
When the lithium ion conductivity of the sulfide-based inorganic solid electrolyte material according to the present embodiment is at least the above lower limit, a lithium ion battery with even better battery characteristics can be obtained. Furthermore, by using such a sulfide-based inorganic solid electrolyte material, it is possible to obtain a lithium ion battery with even better input/output characteristics.

The shape of the sulfide-based inorganic solid electrolyte material according to the present embodiment may be, for example, particulate.
The particulate sulfide-based inorganic solid electrolyte material according to the present embodiment is not particularly limited, but the average particle diameter _d50 in the weight-based particle size distribution by laser diffraction scattering particle size distribution measurement is preferably 1 μm or more and 100 μm or less. , more preferably 3 μm or more and 80 μm or less, still more preferably 5 μm or more and 60 μm or less.
By setting the average particle diameter _d50 of the sulfide-based inorganic solid electrolyte material within the above range, good handling properties can be maintained and lithium ion conductivity can be further improved.

The sulfide-based inorganic solid electrolyte material according to this embodiment preferably has excellent electrochemical stability. Here, the electrochemical stability refers to, for example, the property of being difficult to be oxidized and reduced in a wide voltage range. More specifically, in the sulfide-based inorganic solid electrolyte material according to the present embodiment, the sulfide-based inorganic solid electrolyte material measured under the conditions of a temperature of 25° C., a sweep voltage range of 0 to 5 V, and a voltage sweep rate of 5 mV / sec. is preferably 0.50 μA or less, more preferably 0.20 μA or less, even more preferably 0.10 μA or less, and even more preferably 0.05 μA or less. It is preferably 0.03 μA or less, and particularly preferably 0.03 μA or less.
When the maximum value of the oxidative decomposition current of the sulfide-based inorganic solid electrolyte material is equal to or less than the upper limit, oxidative decomposition of the sulfide-based inorganic solid electrolyte material in the lithium ion battery can be suppressed, which is preferable.
Although the lower limit of the maximum oxidative decomposition current of the sulfide-based inorganic solid electrolyte material is not particularly limited, it is, for example, 0.0001 μA or more.

The sulfide-based inorganic solid electrolyte material according to this embodiment can be used for any application that requires lithium ion conductivity. Among them, the sulfide-based inorganic solid electrolyte material according to the present embodiment is preferably used for lithium ion batteries. More specifically, it is used for positive electrode active material layers, negative electrode active material layers, electrolyte layers and the like in lithium ion batteries. Furthermore, the sulfide-based inorganic solid electrolyte material according to the present embodiment is suitably used for a positive electrode active material layer, a negative electrode active material layer, a solid electrolyte layer, etc. It is particularly suitably used for a solid electrolyte layer that constitutes a battery.
An example of an all-solid-state lithium ion battery to which the sulfide-based inorganic solid electrolyte material according to the present embodiment is applied is one in which a positive electrode, a solid electrolyte layer, and a negative electrode are laminated in this order.

[Method for producing sulfide-based inorganic solid electrolyte material]
Next, a method for producing a sulfide-based inorganic solid electrolyte material according to this embodiment will be described.
The method for producing a sulfide-based inorganic solid electrolyte material according to this embodiment is different from the conventional method for producing a sulfide-based inorganic solid electrolyte material. That is, the sulfide-based inorganic solid electrolyte material in which the amount of hydrogen sulfide generated is equal to or less than the above upper limit is obtained by (1) highly controlling the composition ratio of the sulfide-based inorganic solid electrolyte material; The process of vitrifying the composition and the process of annealing treatment are continuously performed, and the manufacturing method is improved by applying stronger shearing force and compressive force than before to produce a sulfide-based inorganic solid electrolyte material. You can get it for the first time by hiring.
However, on the premise that the sulfide-based inorganic solid electrolyte material according to the present embodiment adopts the above two points of manufacturing method, specific manufacturing conditions such as mixing conditions of various raw materials are various. can be adopted.
Hereinafter, the method for producing the sulfide-based inorganic solid electrolyte material according to this embodiment will be described more specifically.

The sulfide-based inorganic solid electrolyte material according to this embodiment can be obtained, for example, by a production method including the following steps (A), (B) and (C). Moreover, the method for producing a sulfide-based inorganic solid electrolyte material according to the present embodiment may further include the following steps (D) and (E), if necessary.
Step (A): A step of preparing a raw material inorganic composition containing two or more raw material inorganic compounds. A step of vitrifying raw material inorganic compounds while chemically reacting with each other to obtain a sulfide-based inorganic solid electrolyte material in a vitreous state. and mechanically annealing the sulfide-based inorganic solid electrolyte material in a vitreous state to crystallize at least a portion thereof. In the meantime, a step of crystallizing the raw material inorganic composition prepared in step (A) by heating the raw material inorganic composition Step (E): pulverizing, classifying, or granulation process

According to the method for producing a sulfide-based inorganic solid electrolyte material according to the present embodiment, the vitrification step (B) and the annealing treatment step (C) are continuously performed using a pulverizing device that combines shear stress and compressive stress. Therefore, compared to conventional production methods, strong shear stress and compressive stress can be applied to the inorganic composition, so that frictional heat between the particles constituting the inorganic composition can be generated more effectively. . Therefore, according to the method for producing a sulfide-based inorganic solid electrolyte material according to the present embodiment, heat can be more effectively transferred to the sulfide-based inorganic solid electrolyte material in a vitreous state. It is considered that a sulfide-based inorganic solid electrolyte material having a novel structure different from that of the conventional method has been realized.

(Step (A) of preparing raw material inorganic composition)
First, a raw material inorganic composition containing two or more kinds of inorganic compounds such as lithium sulfide, phosphorus sulfide, and lithium nitride in a specific ratio is prepared. Here, the mixing ratio of each raw material in the raw material inorganic composition is adjusted so that the resulting sulfide-based inorganic solid electrolyte material has a desired composition ratio.
The method for mixing each raw material is not particularly limited as long as it is a mixing method that can uniformly mix each raw material. , a drum mixer, a V-shaped mixer, etc.), a kneader, a twin-screw kneader, an airflow pulverizer, or the like.
Mixing conditions such as stirring speed, treatment time, temperature, reaction pressure, and gravitational acceleration applied to the mixture when mixing the raw materials can be appropriately determined according to the throughput of the mixture.

Lithium sulfide used as a raw material is not particularly limited, and commercially available lithium sulfide may be used. For example, lithium sulfide obtained by reaction of lithium hydroxide and hydrogen sulfide may be used. From the viewpoint of obtaining a high-purity sulfide-based inorganic solid electrolyte material and from the viewpoint of suppressing side reactions, it is preferable to use lithium sulfide with few impurities.
Here, in this embodiment, lithium sulfide also includes lithium polysulfide.

Phosphorus sulfide used as _a raw material is not particularly limited, and commercially available phosphorus sulfides _{(eg, P2S5, P4S3, P4S7 , P4S5 , etc. ) can} be used. From the viewpoint of obtaining a high-purity sulfide-based inorganic solid electrolyte material and from the viewpoint of suppressing side reactions, it is preferable to use phosphorus sulfide with few impurities. In place of phosphorus sulfide, elemental phosphorus (P) and elemental sulfur (S) can also be used in a corresponding molar ratio. Elementary phosphorus (P) and elemental sulfur (S) can be used without particular limitation as long as they are industrially produced and sold.

Lithium nitride may be used as the raw material. Here, since nitrogen in lithium nitride is discharged into the system as _N2 , by using lithium nitride as an inorganic compound that is a raw material, a sulfide-based inorganic solid containing Li, P, and S as constituent elements It becomes possible to increase only the Li composition in the electrolyte material.
The lithium nitride according to the present embodiment is not particularly limited, and commercially available lithium nitride (e.g., Li ₃ N, etc.) may be used. For example, metal lithium (e.g., Li foil) and nitrogen gas Lithium nitride obtained by the reaction of may be used. From the viewpoint of obtaining a high-purity solid electrolyte material and from the viewpoint of suppressing side reactions, it is preferable to use lithium nitride with few impurities.

(Vitrification step (B) and annealing treatment step (C))
Subsequently, by mechanically treating the raw material inorganic composition using a pulverizer that combines shear stress and compressive stress, the inorganic composition is vitrified while chemically reacting two or more of the inorganic compounds. A vitrification step (B) is performed. Next, following the vitrification step (B), the sulfide-based inorganic solid electrolyte material in the vitrified state is mechanically annealed using the crushing device used in the vitrification step (B), An annealing step (C) for crystallizing at least a portion is performed.
That is, in the method for producing a sulfide-based inorganic solid electrolyte material according to the present embodiment, the vitrification step (B) and the annealing treatment step (C) are continuously performed using a pulverizing device that combines shear stress and compressive stress. Do. Here, the vitrification step (B) and the annealing treatment step (C) need not be clearly distinguished, and the vitrification step (B) may gradually change to the annealing treatment step (C). included.

In the vitrification step (B) in the method for producing a sulfide-based inorganic solid electrolyte material according to the present embodiment, the inorganic composition is mechanically treated using a pulverizing device that combines shear stress and compressive stress to obtain 2 The sulfide-based inorganic solid electrolyte material is vitrified while chemically reacting at least one kind of inorganic compound. Then, even after the inorganic composition is vitrified, the mechanical treatment using this crusher is continuously performed to anneal the vitrified sulfide-based inorganic solid electrolyte material. Here, when shear stress and compressive stress are continuously applied to the vitrified sulfide-based inorganic solid electrolyte material using a pulverizer that combines shear stress and compressive stress, the sulfide-based inorganic solid electrolyte material is The vitrified sulfide-based inorganic solid electrolyte material is heated by frictional heat between constituent particles, and as a result, the vitrified sulfide-based inorganic solid electrolyte material is annealed and partially crystallized. That is, in the annealing treatment step (C) in the method for producing a sulfide-based inorganic solid electrolyte material according to the present embodiment, shear stress and compressive stress are applied to the vitrified sulfide-based inorganic solid electrolyte material. Heat can anneal the vitrified sulfide-based inorganic solid electrolyte material.
By performing the annealing treatment step (C), at least part of the vitrified sulfide-based inorganic solid electrolyte material is crystallized, and a sulfide-based inorganic solid electrolyte material in a glass-ceramics state can be obtained.

The heating temperature of the vitrified sulfide-based inorganic solid electrolyte material in the annealing step (C) is preferably in the range of 200° C. or higher and 500° C. or lower, and in the range of 220° C. or higher and 350° C. or lower. is more preferred.

In the annealing treatment step (C), mechanical treatment is performed until a diffraction peak different from that of the vitrified sulfide-based inorganic solid electrolyte material is observed in the spectrum obtained by X-ray diffraction using CuKα rays as a radiation source. is preferred. Here, the fact that a diffraction peak different from that of the vitrified sulfide-based inorganic solid electrolyte material is observed means that at least a portion of the vitrified sulfide-based inorganic solid electrolyte material is crystallized into a glass-ceramic state. It is thought that it means that there is

The mechanical treatment in the vitrification step (B) and the annealing treatment step (C) includes mechanically colliding two or more inorganic compounds to vitrify the inorganic composition while causing a chemical reaction, Annealing treatment can be applied to the vitrified inorganic composition, and examples thereof include mechanochemical treatment. Here, the mechanochemical treatment is a method of applying mechanical energy such as shear force or impact force to the target composition.

In the vitrification step (B) and the annealing treatment step (C), the mechanical treatment is preferably dry. This eliminates the need to remove the liquid component such as the organic solvent from the vitrified sulfide-based inorganic solid electrolyte material, thereby further improving the productivity of the sulfide-based inorganic solid electrolyte material. Also, the reaction between the sulfide-based inorganic solid electrolyte material and the organic solvent can be prevented. Furthermore, since liquid components such as organic solvents are not used, safety in the manufacturing process can be further improved.

Examples of pulverizing devices that combine shear stress and compressive stress according to the present embodiment include roll mills; rock drills, vibration drills, impact drivers, etc. rotating/impact pulverizing device consisting of a mechanism; high-pressure gliding rolls; and vertical mills such as a roller-type vertical mill and a ball-type vertical mill. Among these, a roll mill and a vertical mill are preferable, and a roll mill is more preferable, from the viewpoint of excellent continuous productivity.

Moreover, it is preferable that the roll mill according to the present embodiment is composed of three or more rolls. As a result, the vitrification treatment and the annealing treatment can be performed more continuously, so that the productivity of the resulting sulfide-based inorganic solid electrolyte material can be further improved.

Moreover, the diameter of the rolls constituting the roll mill according to the present embodiment is preferably 40 mm or more, more preferably 50 mm or more, and even more preferably 60 mm or more. As a result, even stronger shear stress and compressive stress can be applied to the raw material inorganic composition present between the rolls, so that vitrification of the raw material inorganic composition can proceed more efficiently. Furthermore, since stronger shear stress and compressive stress can be applied to the vitrified sulfide-based inorganic solid electrolyte material existing between the rolls, frictional heat between the particles that make up the sulfide-based inorganic solid electrolyte material can be generated more effectively, and as a result, the annealing treatment of the vitrified sulfide-based inorganic solid electrolyte material can be proceeded more effectively.

Further, in the roll mill according to this embodiment, it is preferable that the adjacent rolls have different rotation speeds. As a result, shear stress can be applied more effectively to the inorganic composition existing between the rolls while applying compressive stress, so that vitrification of the raw material inorganic composition can be proceeded more efficiently.
In addition, in the roll mill according to the present embodiment, it is preferable that adjacent rolls rotate in different directions. Thereby, compressive stress can be applied more effectively to the inorganic composition existing between the rolls.

At least the surfaces of the rolls constituting the roll mill according to this embodiment are preferably made of at least one material selected from ceramic materials and metal materials.
Examples of metal materials include centrifugal chilled steel, SUS, Cr-plated SUS, and Cr-plated hardened steel.
Further, when at least the surfaces of the rolls constituting the roll mill according to the present embodiment are made of a ceramic material, it is possible to suppress the contamination of the obtained sulfide-based inorganic solid electrolyte material with unnecessary metal components derived from the rolls. It is possible to obtain a sulfide-based inorganic solid electrolyte material with a higher purity.
Examples of such ceramic materials include stabilized zirconia, alumina, silicon carbide, and silicon nitride.
Among these, alumina is preferable because it is relatively inexpensive and can produce large parts with high precision.

Hereinafter, the case of performing the vitrification step (B) and the annealing treatment step (C) according to the present embodiment using a three-roll mill consisting of three rolls as a pulverizing device will be specifically described.
A three-roll mill, for example, consists of a first roll, a second roll, a third roll and blades.
First, a raw material inorganic composition containing two or more inorganic compounds is charged between the first roll, which is the gap between the first roll and the second roll.
The raw material inorganic composition entering between the first rolls is compressed by the first roll and the second roll. Here, by adopting different rotation speeds in the first roll and the second roll, while applying compressive stress to the raw material inorganic composition entering between the first rolls, shear stress can be more effectively applied. can be provided, the vitrification and annealing treatment of the inorganic composition can proceed more efficiently.

Here, it is preferable that the rotational speed of the rolls is faster for the second roll than for the first roll, and faster for the third roll than for the second roll. That is, in the roll mill according to the present embodiment, the plurality of rolls are set so that the rotation speed gradually increases from the roll on which the inorganic composition is introduced toward the roll on which the inorganic composition is discharged. preferably. 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 processing amount of the inorganic composition, and the like. In this case, if the speed of the first roll is 1, the speed of the second roll is 2 to 4, and the speed of the third roll is 5 to 9, so that the rotation speed is increased toward the roll on the discharged side. can do. By doing so, the inorganic composition adhering to the roll can be transferred to the surface of the adjacent roll more efficiently, and as a result, the productivity of the sulfide-based inorganic solid electrolyte material can be further improved. .

Next, after passing the inorganic composition between the first rolls, the inorganic composition is passed between the second rolls adjacent between the first rolls. By repeating this operation, the inorganic composition can be vitrified and annealed continuously. Here, the inorganic composition adheres to the surface of the second roll due to the compressive stress of the first roll and the second roll, so it can be continuously transferred between the second rolls. .
The sulfide-based inorganic solid electrolyte material obtained by passing between the second rolls adheres to the surface of the third roll, and can be scraped off with a blade, for example.
In addition, if the sulfide-based inorganic solid electrolyte material obtained by passing between the second rolls is insufficiently vitrified or annealed, the above-mentioned material is passed between the first rolls and between the second rolls. It is preferred to repeat the treatment. Alternatively, it is preferable that the number of rolls in the roll mill is set to 4 or more and a mechanical treatment combining shear stress and compressive stress is further 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, more preferably 10 μm or more and 50 μm or less, from the viewpoint of applying compressive stress to the inorganic composition more effectively.
Moreover, in the roll mill according to the present embodiment, the rotational speed of the rolls is preferably 20 rpm or more and 1000 rpm or less, more preferably 100 rpm or more and 800 rpm or less, from the viewpoint of applying shear stress to the inorganic composition more effectively.
However, the distance between the rolls and the rotation speed of the rolls are not limited to the above ranges, since they are appropriately determined depending on the type of inorganic composition, the amount of treatment, the number of rolls, and the like.

Moreover, the mechanical treatment in the vitrification step (B) and the annealing treatment step (C) is preferably performed in an inert atmosphere. Thereby, the reaction between the inorganic composition and water vapor, oxygen, or the like can be suppressed.
In addition, the term "inactive atmosphere" refers to a vacuum atmosphere or an inert gas atmosphere. In the inert atmosphere, the dew point is preferably −50° C. or lower, more preferably −60° C. or lower, in order to avoid contact with moisture. The term "inactive gas atmosphere" means an atmosphere of an inert gas such as argon gas, helium gas, or nitrogen gas. These inert gases are preferably as high-purity as possible in order to prevent contamination of products with impurities. The method of introducing the inert gas into the mixed system is not particularly limited as long as the inside of the mixed system is filled with an inert gas atmosphere. methods and the like.

Mixing conditions such as rotation speed, treatment time, and temperature when vitrifying the raw material inorganic composition or when annealing the vitrified sulfide-based inorganic solid electrolyte material depend on the type and amount of the inorganic composition. It can be determined as appropriate. In general, the faster the rotation speed, the faster the glass formation speed, so the time of the vitrification step (B) is shortened. ) becomes shorter.
Usually, when X-ray diffraction analysis is performed using CuKα rays as a radiation source, if the diffraction peak of the inorganic composition before the vitrification step (B) disappears or decreases, the inorganic composition is vitrified. It can be determined that In addition, usually, when X-ray diffraction analysis using CuKα rays as a radiation source is performed, the inorganic composition before performing the vitrification step (B) or the sulfide-based inorganic solid before performing the annealing treatment step (C) If a new diffraction peak different from that of the electrolyte material is generated, it can be determined that the inorganic composition has been annealed and is in a glass-ceramic state.

(Crystallization step (D))
In the method for producing a sulfide-based inorganic solid electrolyte material according to the present embodiment, heating the raw material inorganic composition prepared in step (A) between the preparation step (A) and the vitrification step (B). A step of crystallizing the starting inorganic composition may be further performed.
That is, the vitrification step (B) may be performed on the crystallized raw material inorganic composition.
By performing the crystallization step (D) before the vitrification step (B), the step (B) of vitrifying the starting inorganic composition can be significantly shortened, and as a result, the sulfide-based inorganic solid It is possible to further shorten the production time of the electrolyte material. Although the reason for this is not clear, the following reasons are presumed.
First, inorganic compositions in the glassy state are metastable. On the other hand, an inorganic composition in a crystalline state is in a stable state. Further, when an inorganic composition containing two or more kinds of inorganic compounds is heated, energy higher than the activation energy can be easily applied. can get. Since the free energy in the stable state is close to the free energy in the metastable state, the crystal state in the stable state can be changed to the glassy state in the metastable state with less energy.
For the above reasons, the step (D) of crystallizing the inorganic composition is performed before the step (B) of vitrifying the inorganic composition, and the inorganic composition is in a stable crystalline state in advance. , the metastable glassy state can be achieved with less energy, and the process of vitrifying the inorganic composition can be greatly shortened.

The temperature at which the inorganic composition is heated is not particularly limited. more preferred.

The heating time of the inorganic composition is not particularly limited as long as the inorganic composition can be crystallized. hours or more and 10 hours or less. Although the heating method is not particularly limited, for example, a method using a kiln can be mentioned. The conditions such as the temperature and time during such heating can be appropriately adjusted in order to optimize the properties of the sulfide-based inorganic solid electrolyte material of the present embodiment.

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

(Step (E) of pulverizing, classifying, or granulating)
In the method for producing a sulfide-based inorganic solid electrolyte material of the present embodiment, a step of pulverizing, classifying, or granulating the obtained sulfide-based inorganic solid electrolyte material may be further performed, if necessary. For example, a sulfide-based inorganic solid electrolyte material having a desired particle size can be obtained by finely pulverizing and then adjusting the particle size by classification or granulation. The pulverization method is not particularly limited, and known pulverization methods such as mixer, airflow pulverization, mortar, rotary mill, and coffee mill can be used. Moreover, the classification method is not particularly limited, and a known method such as a sieve can be used.
These pulverization or classification are preferably carried out under an inert gas atmosphere or a vacuum atmosphere from the viewpoint of preventing contact with moisture in the air.

[Solid electrolyte]
Next, the solid electrolyte according to this embodiment will be described. The solid electrolyte according to this embodiment includes the sulfide-based inorganic solid electrolyte material according to this embodiment.
The solid electrolyte according to the present embodiment is not particularly limited, but as a component other than the sulfide-based inorganic solid electrolyte material according to the present embodiment, for example, the above-described present embodiment within a range that does not impair the object of the present invention It may contain a solid electrolyte material of a different type from the sulfide-based inorganic solid electrolyte material according to .

The solid electrolyte according to this embodiment may contain a solid electrolyte material of a different type from the above-described sulfide-based inorganic solid electrolyte material according to this embodiment. The type of solid electrolyte material different from the sulfide-based inorganic solid electrolyte material according to the present embodiment is not particularly limited as long as it has ion conductivity and insulation, but is generally used for lithium ion batteries. can be used. For example, inorganic solid electrolyte materials such as sulfide-based inorganic solid electrolyte materials, oxide-based inorganic solid electrolyte materials, and other lithium-based inorganic solid electrolyte materials that are different from the sulfide-based inorganic solid electrolyte material according to the present embodiment; Organic solid electrolyte materials such as polymer electrolytes can be mentioned.

Examples of the sulfide-based inorganic solid electrolyte material different from the sulfide-based inorganic solid electrolyte material according to the present embodiment described above include Li ₂ SP ₂ S ₅ material, Li ₂ S-SiS ₂ material, Li ₂ S - _GeS2 material, _{Li2S - Al2S3} material _{, Li2S - SiS2} - _Li3PO4 material, _Li2SP2S5 - _GeS2 material _{, Li2S} - _{Li2OP 2S5 - SiS2} material, _Li2S - _GeS2 - _{P2S5 - SiS2} material _{, Li2S} - _SnS2 - _{P2S5 - SiS2} material, _{Li2SP2S5 -} Li _3N materials, Li ₂ S _2+X -P ₄ S ₃ materials, Li ₂ SP ₂ S ₅ -P ₄ S ₃ materials, and the like. These may be used individually by 1 type, and may be used in combination of 2 or more type.
Among these materials, the Li ₂ SP ₂ S ₅ material is preferable from the viewpoint of excellent lithium ion conductivity and stability that does not cause decomposition or the like in a wide voltage range. Here, for example, the Li ₂ SP ₂ S ₅ material is a solid 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 electrolyte material.
Here, in this embodiment, lithium sulfide also includes lithium polysulfide.

Examples of the oxide-based inorganic solid electrolyte material include NASICON type materials such as LiTi ₂ (PO ₄ ) ₃ , LiZr ₂ (PO ₄ ) ₃ , LiGe ₂ (PO ₄ ) ₃ , (La _{0.5 + x} Li _{0.5 -3x} ) Perovskite type such as TiO ₃ , 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 (where x is 0<x≦1), LiN, LiI, LISICON, and the like. be done.
Furthermore, glass-ceramics obtained by depositing crystals of these inorganic solid electrolytes can also be used as inorganic solid electrolyte materials.

As the organic solid electrolyte material, for example, polymer electrolytes such as dry polymer electrolytes and gel electrolytes can be used.
As the polymer electrolyte, those generally used for lithium ion batteries can be used.

[Solid electrolyte membrane]
Next, the solid electrolyte membrane according to this embodiment will be described.
The solid electrolyte membrane according to this embodiment contains, as a main component, a solid electrolyte containing the above-described sulfide-based inorganic solid electrolyte material according to this embodiment.

The solid electrolyte membrane according to the present embodiment is used, for example, as a solid electrolyte layer that constitutes an all-solid-state lithium ion battery.
An example of an all-solid-state lithium ion battery to which the solid electrolyte membrane according to the present embodiment is applied is one in which a positive electrode, a solid electrolyte layer, and a negative electrode are laminated in this order. In this case, the solid electrolyte layer is composed of a solid electrolyte membrane.

The average thickness of the solid electrolyte membrane according to the present embodiment is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 200 μm or less, and still more preferably 20 μm or more and 100 μm or less. When the average thickness of the solid electrolyte membrane is equal to or greater than the lower limit, it is possible to further suppress the lack of the solid electrolyte and the occurrence of cracks on the surface of the solid electrolyte membrane. Moreover, the impedance of a solid electrolyte membrane can be further reduced as the average thickness of the said solid electrolyte membrane is below the said upper limit. As a result, the battery characteristics of the obtained all-solid-state lithium ion battery can be further improved.

The solid electrolyte membrane according to this embodiment is preferably a pressure-molded body of a particulate solid electrolyte containing the above-described sulfide-based inorganic solid electrolyte material according to this embodiment. That is, it is preferable to pressurize the particulate solid electrolyte to form a solid electrolyte membrane having a certain strength due to the anchoring effect between the solid electrolyte materials.
By forming a pressure-molded body, the solid electrolytes are bonded to each other, and the strength of the obtained solid electrolyte membrane is further increased. As a result, it is possible to further suppress the loss of the solid electrolyte and the occurrence of cracks on the surface of the solid electrolyte membrane.

The content of the sulfide-based inorganic solid electrolyte material according to the present embodiment in the solid electrolyte membrane according to the present embodiment is preferably 50% by mass or more, when the entire solid electrolyte membrane is 100% by mass. It is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more. As a result, the contact between the solid electrolytes is improved, and the interfacial contact resistance of the solid electrolyte membrane can be reduced. As a result, the lithium ion conductivity of the solid electrolyte membrane can be further improved. By using such a solid electrolyte membrane with excellent lithium ion conductivity, the battery characteristics of the obtained all-solid-state lithium ion battery can be further improved.
Although the upper limit of the content of the sulfide-based inorganic solid electrolyte material according to the present embodiment in the solid electrolyte membrane according to the present embodiment is not particularly limited, it is, for example, 100% by mass or less.

The planar shape of the solid electrolyte membrane is not particularly limited, and can be appropriately selected according to the shape of the electrode or current collector. For example, it can be rectangular.

Further, the solid electrolyte membrane according to the present embodiment may contain a binder resin, and the content of the binder resin is preferably less than 0.5% by mass when the solid electrolyte membrane as a whole is 100% by mass. , more preferably 0.1% by mass or less, still more preferably 0.05% by mass or less, and even more preferably 0.01% by mass or less. Further, the solid electrolyte membrane according to this embodiment preferably does not substantially contain a binder resin, and most preferably does not contain a binder resin.
As a result, the contact between the solid electrolytes is improved, and the interfacial contact resistance of the solid electrolyte membrane can be reduced. As a result, the lithium ion conductivity of the solid electrolyte membrane can be further improved. By using such a solid electrolyte membrane with excellent lithium ion conductivity, the battery characteristics of the obtained all-solid-state lithium ion battery can be improved.
The phrase "substantially free of binder resin" means that it may be contained to the extent that the effects of the present embodiment are not impaired. Further, when an adhesive resin layer is provided between the solid electrolyte layer and the positive electrode or the negative electrode, the adhesive resin derived from the adhesive resin layer present in the vicinity of the interface between the solid electrolyte layer and the adhesive resin layer is referred to as the "solid electrolyte It is excluded from "binder resin in the film".

The binder resin refers to a binder generally used in lithium ion batteries to bind between inorganic solid electrolyte materials. Examples include polyvinyl alcohol, polyacrylic acid, carboxymethylcellulose, polytetrafluoro Examples include ethylene, polyvinylidene fluoride, styrene-butadiene rubber, and polyimide.

The solid electrolyte membrane according to the present embodiment can be produced, for example, by depositing a particulate solid electrolyte on the cavity surface of the mold or on the surface of the base material in the form of a film, and then pressing the solid electrolyte deposited in the form of a film. Obtainable.
The method of pressurizing the solid electrolyte is not particularly limited. For example, when the particulate solid electrolyte is deposited on the cavity surface of the mold, pressing is performed using a mold and a pressing mold, and the particulate solid electrolyte is applied to the substrate surface. When it is deposited on the surface, press using a mold and stamping die, roll press, flat plate press, or the like can be used.
The pressure to pressurize the solid electrolyte is, for example, 10 MPa or more and 500 MPa or less.

In addition, if necessary, the inorganic solid electrolyte deposited in the form of a film may be pressurized and heated. When heat and pressure are applied, the solid electrolytes are fused and bonded to each other, and the strength of the obtained solid electrolyte membrane is further increased. As a result, it is possible to further suppress the loss of the solid electrolyte and the occurrence of cracks on the surface of the solid electrolyte membrane.
The temperature for heating the solid electrolyte is, for example, 40° C. or higher and 500° C. or lower.

[Lithium-ion battery]
FIG. 1 is a cross-sectional view showing an example of the structure of a lithium ion battery 100 according to an embodiment of the invention.
A lithium ion battery 100 according to the present embodiment includes, for example, a positive electrode 110 including a positive electrode active material layer 101 , an electrolyte layer 120 , and a negative electrode 130 including a negative electrode active material layer 103 . At least one of the positive electrode active material layer 101, the negative electrode active material layer 103, and the electrolyte layer 120 contains the sulfide-based inorganic solid electrolyte material according to this embodiment. Moreover, all of the positive electrode active material layer 101, the negative electrode active material layer 103, and the electrolyte layer 120 preferably contain the sulfide-based inorganic solid electrolyte material according to this embodiment. In this embodiment, a layer containing a positive electrode active material is referred to as a positive electrode active material layer 101 unless otherwise specified. The positive electrode 110 may further include a current collector 105 in addition to the positive electrode active material layer 101 or may not include the current collector 105 as necessary. In this embodiment, a layer containing a negative electrode active material is referred to as a negative electrode active material layer 103 unless otherwise specified. The negative electrode 130 may further include a current collector 105 in addition to the negative electrode active material layer 103 or may not include the current collector 105 as necessary.
The shape of the lithium-ion battery 100 according to this embodiment is not particularly limited, and may be cylindrical, coin-shaped, rectangular, film-shaped or any other shape.

The lithium ion battery 100 according to this embodiment is manufactured according to a generally known method. For example, the positive electrode 110, the electrolyte layer 120, and the negative electrode 130 are stacked to form a cylindrical shape, coin shape, square shape, film shape, or any other shape, and if necessary, by enclosing a non-aqueous electrolyte solution. produced.

(positive electrode)
The positive electrode 110 is not particularly limited, and one commonly used in lithium ion batteries can be used. Although the positive electrode 110 is not particularly limited, it can be manufactured according to a generally known method. For example, it can be obtained by forming a positive electrode active material layer 101 containing a positive electrode active material on the surface of a current collector 105 such as an aluminum foil.
The thickness and density of the positive electrode active material layer 101 are not particularly limited because they are appropriately determined according to the intended use of the battery, and can be set according to generally known information.

The positive electrode active material layer 101 contains a positive electrode active material.
The positive electrode active material is not particularly limited, and generally known materials can be used. 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 ), composite oxides such as olivine-type lithium phosphorous oxide (LiFePO ₄ ); highly conductive oxides such as polyaniline and polypyrrole; Molecules: Li ₂ S, CuS, Li—Cu—S compounds, TiS ₂ , FeS, MoS ₂ , Li—Mo—S compounds, Li—Ti—S compounds, Li—VS compounds, Li—Fe—S compounds sulfide-based positive electrode active materials such as; sulfur-impregnated acetylene black, sulfur-impregnated porous carbon, mixed powder of sulfur and carbon, and other materials using sulfur as an active material; These positive electrode active materials may be used individually by 1 type, and may be used in combination of 2 or more type.
Among these, a sulfide-based positive electrode active material is preferable from the viewpoint of having a higher discharge capacity density and more excellent cycle characteristics, and Li-Mo-S compounds, Li-Ti-S compounds, Li-VS One or two or more selected from compounds are more preferable.

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

Although the positive electrode active material layer 101 is not particularly limited, it may contain one or more materials selected from binder resins, thickeners, conductive aids, solid electrolyte materials, etc., as components other than the positive electrode active material. . Each material will be described below.

The positive electrode active material layer 101 may contain a binder resin that serves to bind the positive electrode active materials together and the positive electrode active material and the current collector 105 .
The binder resin according to the present embodiment is not particularly limited as long as it is a normal binder resin that can be used for lithium ion batteries. Butadiene-based rubber, polyimide, and the like can be mentioned. These binders may be used individually by 1 type, and may be used in combination of 2 or more types.

The positive electrode active material layer 101 may contain a thickening agent in order to ensure the fluidity of the slurry suitable for coating. The thickening agent is not particularly limited as long as it is a normal thickening agent that can be used for lithium ion batteries. Examples thereof include water-soluble polymers such as polycarboxylic acid, polyethylene oxide, polyvinylpyrrolidone, polyacrylate, and polyvinyl alcohol. These thickeners may be used singly or in combination of two or more.

The positive electrode active material layer 101 may contain a conductive aid from the viewpoint of improving the conductivity of the positive electrode 110 . The conductive aid is not particularly limited as long as it is a normal conductive aid that can be used in lithium ion batteries, and examples thereof include carbon black such as acetylene black and ketjen black, and carbon materials such as vapor grown carbon fiber. .

The positive electrode according to the present embodiment may contain a solid electrolyte containing the sulfide-based inorganic solid electrolyte material according to the present embodiment described above, or a different type of solid electrolyte from the sulfide-based inorganic solid electrolyte material according to the present embodiment. A solid electrolyte containing a solid electrolyte material may be included. The type of solid electrolyte material different from the sulfide-based inorganic solid electrolyte material according to the present embodiment is not particularly limited as long as it has ion conductivity and insulation, but is generally used for lithium ion batteries. can be used. Examples include inorganic solid electrolyte materials such as sulfide-based inorganic solid electrolyte materials, oxide-based inorganic solid electrolyte materials, and other lithium-based inorganic solid electrolyte materials; and organic solid electrolyte materials such as polymer electrolytes. More specifically, the inorganic solid electrolyte materials mentioned in the description of the solid electrolyte according to this embodiment can be used.

The mixing ratio of various materials in the positive electrode active material layer 101 is not particularly limited because it is appropriately determined according to the intended use of the battery, and can be set according to generally known information.

(negative electrode)
The negative electrode 130 is not particularly limited, and those commonly used in lithium ion batteries can be used. Although the negative electrode 130 is not particularly limited, it can be manufactured according to a generally known method. For example, it can be obtained by forming a negative electrode active material layer 103 containing a negative electrode active material on the surface of a current collector 105 such as copper.
The thickness and density of the negative electrode active material layer 103 are not particularly limited because they are appropriately determined according to the intended use of the battery, and can be set according to generally known information.

The negative electrode active material layer 103 contains a negative electrode active material.
The negative electrode active material is not particularly limited as long as it is a normal negative electrode active material that can be used for the negative electrode of a lithium ion battery. Examples include natural graphite, artificial graphite, resin carbon, carbon fiber, activated carbon, hard carbon, and soft carbon. Carbonaceous materials such as; lithium, lithium alloys, tin, tin alloys, silicon, silicon alloys, gallium, gallium alloys, indium, indium alloys, aluminum, aluminum alloys, etc.; metallic materials such as polyacene, polyacetylene, polypyrrole, etc. conductive polymer; lithium-titanium composite oxide (e.g., Li ₄ Ti ₅ O ₁₂ ), and the like. These negative electrode active materials may be used singly or in combination of two or more.

Although the negative electrode active material layer 103 is not particularly limited, it may contain, as components other than the negative electrode active material, one or more materials selected from, for example, binder resins, thickeners, conductive aids, solid electrolyte materials, and the like. . Although these materials are not particularly limited, for example, the same materials as those used for the positive electrode 110 described above can be used.
The mixing ratio of various materials in the negative electrode active material layer 103 is not particularly limited because it is appropriately determined according to the intended use of the battery, and can be set according to generally known information.

(Electrolyte layer)
Next, the electrolyte layer 120 is described. The electrolyte layer 120 is a layer formed between the positive electrode active material layer 101 and the negative electrode active material layer 103 .
The electrolyte layer 120 includes a separator impregnated with a non-aqueous electrolyte and a solid electrolyte layer containing a solid electrolyte.

The separator according to the present embodiment is not particularly limited as long as it has the function of electrically insulating the positive electrode 110 and the negative electrode 130 and allowing lithium ions to pass through. For example, a porous film can be used.

A microporous polymer film is preferably used as the porous membrane, and examples of the material include polyolefin, polyimide, polyvinylidene fluoride, polyester and the like. In particular, porous polyolefin films are preferred, and specific examples include porous polyethylene films, porous polypropylene films, and the like.

The non-aqueous electrolytic solution is obtained by dissolving an electrolyte in a solvent.
Any known lithium salt can be used as the electrolyte, and the electrolyte may be selected according to the type of the active material. For example, _LiClO4 , _LiBF6 , _{LiPF6 , LiCF3SO3} , _LiCF3CO2 , _LiAsF6 , _{LiSbF6 , LiB10Cl10} , _{LiAlCl4 ,} LiCl, LiBr, LiB( _C2H5 ) _{4 , CF3} SO ₃ Li, CH ₃ SO ₃ Li, LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , Li(CF ₃ SO ₂ ) ₂ N, lithium lower fatty acid carboxylate, and the like.

The solvent for dissolving the electrolyte is not particularly limited as long as it is commonly used as a liquid for dissolving the electrolyte. Ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC). , diethyl carbonate (DEC), methyl ethyl carbonate (MEC), vinylene carbonate (VC) and other carbonates; γ-butyrolactone, γ-valerolactone and other lactones; trimethoxymethane, 1,2-dimethoxyethane, diethyl ether Ethers such as , 2-ethoxyethane, tetrahydrofuran, and 2-methyltetrahydrofuran; sulfoxides such as dimethylsulfoxide; oxolanes such as 1,3-dioxolane and 4-methyl-1,3-dioxolane; acetonitrile, nitromethane, formamide, Nitrogen-containing compounds such as dimethylformamide; organic acid esters such as methyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, and ethyl propionate; phosphate triesters and diglymes; triglymes; sulfolane, methylsulfolane, etc. sulfolanes; oxazolidinones such as 3-methyl-2-oxazolidinone; sultones such as 1,3-propanesultone, 1,4-butanesultone and naphthsultone; These may be used individually by 1 type, and may be used in combination of 2 or more type.

The solid electrolyte layer according to this embodiment is a layer formed between the positive electrode active material layer 101 and the negative electrode active material layer 103, and is a layer formed of a solid electrolyte containing a solid electrolyte material. The solid electrolyte contained in the solid electrolyte layer is not particularly limited as long as it has lithium ion conductivity. It is preferably an electrolyte.
The content of the solid electrolyte in the solid electrolyte layer according to the present embodiment is not particularly limited as long as the desired insulation is obtained. Above all, it is preferable to be in the range of 50% by volume or more and 100% by volume or less. In particular, in the present embodiment, it is preferable that the solid electrolyte layer is composed only of the solid electrolyte containing the sulfide-based inorganic solid electrolyte material according to the present embodiment.

Moreover, the solid electrolyte layer according to the present embodiment may contain a binder resin. By containing a binder resin, a flexible solid electrolyte layer can be obtained. Examples of the binder resin include fluorine-containing binders such as polytetrafluoroethylene and polyvinylidene fluoride. The thickness of the solid electrolyte layer is, for example, within the range of 0.1 μm or more and 1000 μm or less, and preferably within the range of 0.1 μm or more and 300 μm or less.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than those described above can also be adopted.
It should be noted that the present invention is not limited to the above-described embodiments, and includes modifications, improvements, etc. within the scope of achieving the object of the present invention.

EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples, but the present invention is not limited to these.

[1] Measurement method First, the measurement method in the following examples and comparative examples will be described.

(1) Particle size distribution Particle size distribution of the sulfide-based inorganic solid electrolyte materials obtained in Examples and Comparative Examples by a laser diffraction method using a laser diffraction scattering type particle size distribution analyzer (Malvern, Mastersizer 3000). was measured. From the measurement results, the particle size (D ₅₀ , average particle size) at 50% accumulation in the weight-based cumulative distribution was determined for the sulfide-based inorganic solid electrolyte material.

(2) Measurement of composition ratio The sulfide-based inorganic solid electrolytes obtained in Examples and Comparative Examples were measured by ICP emission spectrometry using an ICP emission spectrometer (manufactured by Seiko Instruments Inc., SPS3000). The mass % of Li, P and S in the material was obtained, and based on this, the molar ratio of each element was calculated.

(3) X-ray diffraction analysis The diffraction spectra of the sulfide-based inorganic solid electrolyte materials obtained in Examples and Comparative Examples were analyzed by X-ray diffraction analysis using an X-ray diffractometer (RINT2000, manufactured by Rigaku Corporation). asked. CuKα rays were used as the radiation source. Here, the maximum diffraction intensity at the diffraction angle 2θ = 35.0 ± 0.1° is defined as the background intensity _IA , and the maximum diffraction peak at the diffraction angle 2θ = 17.2 ± 0.5°. Let _IB be the diffraction intensity, IC be the maximum diffraction intensity of the diffraction peak existing at the diffraction angle 2θ=25.6±0.5°, and _IC be the maximum diffraction intensity at the diffraction angle 2θ=29.2±0.8°. The maximum diffraction intensity of the existing diffraction peak was defined as _ID , and the maximum diffraction intensity of the diffraction peak existing at the diffraction angle 2θ=26.6±0.4° was defined as _IE . Also, _IB / _IA , _IC / _IA , _ID / _IA and _IE / _IA were determined respectively.

(4) Measurement of Lithium Ion Conductivity The sulfide-based inorganic solid electrolyte materials obtained in Examples and Comparative Examples were measured for lithium ion conductivity by an AC impedance method. Further, after exposing 1.0 g of the sulfide-based inorganic solid electrolyte materials obtained in Examples and Comparative Examples to the atmosphere at 25°C for 10 minutes, the lithium ion conductivity of the sulfide-based inorganic solid electrolyte materials was measured. were performed respectively.
Potentiostat/galvanostat SP-300 manufactured by Biologic was used to measure the lithium ion conductivity. The size of the sample was 9.5 mm in diameter and 1.2 to 2.0 mm in thickness. 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 a Li foil electrode. .
Here, the sample for lithium ion conductivity measurement is obtained by pressing 150 mg of the powdery sulfide-based inorganic solid electrolyte material obtained in Examples and Comparative Examples at 270 MPa for 10 minutes using a pressing device. A plate-like sulfide-based inorganic solid electrolyte material having a diameter of 9.5 mm and a thickness of 1.2 to 2.0 mm was used.

(5) Measurement of Maximum Value of Oxidative Decomposition Current Using a pressing device, 120 to 150 mg of the powdery sulfide-based inorganic solid electrolyte materials obtained in Examples and Comparative Examples were pressed at 270 MPa for 10 minutes to obtain a diameter of 9.5 mm. A plate-like sulfide-based inorganic solid electrolyte material (pellet) having a size of 5 mm and a thickness of 1.3 mm was obtained. Next, Li foils as reference and counter electrodes were press-bonded to one surface of the obtained pellet under conditions of 18 MPa for 10 minutes, and SUS314 foil was adhered to the other surface as a working electrode.
Next, using a Potentiostat/Galvanostat SP-300 manufactured by Biologic Inc., the sulfide-based inorganic solid electrolyte material is oxidatively decomposed under conditions of a temperature of 25° C., a sweep voltage range of 0 to 5 V, and a voltage sweep rate of 5 mV/sec. The maximum current value was obtained and evaluated according to the following criteria.
◎: 0.03 μA or less ○: 0.03 μA or less 0.50 μA or less ×: 0.50 μA or less

(6) Measurement of amount of hydrogen sulfide generated In a glove box purged with argon gas, the sulfide-based inorganic solid electrolyte materials (100 mg) obtained in Examples and Comparative Examples were placed in a plastic container, and the plastic container was placed in a glass container. placed on the bottom of a sealed container (capacity 1 L). Next, the closed glass container was taken out into the air at room temperature, and ion-exchanged water (1 mL) was dropped from the top of the closed glass container onto the sulfide-based inorganic solid electrolyte material in the plastic container. Then, 5 minutes after the ion-exchanged water was dropped, a rubber gas absorption bag (manufactured by Okano Seisakusho Co., Ltd., product name: OG-3F-D) attached to a closed glass container was deflated 10 times. After homogenizing the gas atmosphere inside the sealed container manufactured by the company, the concentration of hydrogen sulfide gas was measured at the measurement position shown in FIG.

[2] Production of solid electrolyte material <Example 1>
A sulfide-based inorganic solid electrolyte material was produced by the following procedure.
Li ₂ S (manufactured by Furukawa Co., Ltd., purity 99.9%), P ₂ S ₅ (manufactured by Kanto Chemical Co., Ltd.) and Li ₃ N (manufactured by Furukawa Co., Ltd.) were used as raw materials.
Next, in a glove box, using a crusher, Li ₂ S powder, P ₂ S ₅ powder and Li ₃ N powder (Li ₂ S: P ₂ S ₅ : Li ₃ N = 71.1: 23.7: 5 .3 (mol %)) A starting inorganic composition was prepared by mixing a total of 80 g.
Next, 80 g of the starting inorganic composition was mechanochemically treated with a three-roll mill (BR-100V manufactured by Aimex) to obtain a sulfide-based inorganic solid electrolyte material. Here, the first to third rolls were passed once, and the film was passed 70 times in total. Each roll was made of zirconia (ZrO ₂ ) and had a diameter of 63.5 mm, and the distance between the rolls was 20 μm. Further, the rotation speed of the first roll: the rotation speed of the second roll: the rotation speed of the third roll was set to 1:2.5:6, and the rotation speed of the third roll was set to 700 rpm.
After passing through the first roll to the third roll 70 times, a part of each sample was sampled and each physical property was evaluated. Table 1 shows the results obtained.

<Example 2>
A sulfide-based inorganic solid electrolyte material was produced in the same manner as in Example 1, except that the number of passes through the first roll to the third roll was changed to 40 times, and each evaluation was performed. Table 1 shows the results obtained.

<Example 3>
A sulfide-based inorganic solid electrolyte material was produced in the same manner as in Example 1, except that the number of passes through the first roll to the third roll was changed to 60 times, and each evaluation was performed. Table 1 shows the results obtained.

<Example 4>
The mixing ratio _{of Li2S} powder _{, P2S5} powder and _Li3N powder was changed to _Li2S : _P2S5 : _Li3N =72.6:24.2:3.2 (mol%). A sulfide-based inorganic solid electrolyte material was produced in the same manner as in Example 1, except that it was used, and each evaluation was performed. Table 1 shows the results obtained.

<Example 5>
The mixing ratio _{of Li2S} powder, _P2S5 powder and _Li3N powder was changed to _Li2S : _P2S5 : _{Li3N =} 73.8:24.6:1.6 (mol%). A sulfide-based inorganic solid electrolyte material was produced in the same manner as in Example 1, except that it was used, and each evaluation was performed. Table 1 shows the results obtained.

<Comparative Example 1>
A sulfide-based inorganic solid electrolyte material was produced in the same manner as in Example 1, except that the number of passes through the first roll to the third roll was changed to 10 times. Next, the resulting glassy sulfide-based inorganic solid electrolyte material was transferred to a carbon crucible and annealed at 270° C. for 2 hours in an oven installed in a glove box to obtain a sulfide-based inorganic solid electrolyte material. . Each evaluation was performed. Table 1 shows the results obtained.

<Comparative Example 2>
A sulfide-based inorganic solid electrolyte material was produced by the following procedure.
Li ₂ S (manufactured by Furukawa Co., Ltd., purity 99.9%), P ₂ S ₅ (manufactured by Kanto Chemical Co., Ltd.) and Li ₃ N (manufactured by Furukawa Co., Ltd.) were used as raw materials.
Next, in a glove box, using a crusher, Li ₂ S powder, P ₂ S ₅ powder and Li ₃ N powder (Li ₂ S: P ₂ S ₅ : Li ₃ N = 71.1: 23.7: 5 .3 (mol %)) A starting inorganic composition was prepared by mixing a total of 80 g.
Subsequently, 2 g of the starting inorganic composition and 500 g of ZrO ₂ balls with a diameter of 10 mm were put into an alumina pot (inner volume: 400 mL) in the glove box, and the pot was sealed.
Next, the alumina pot is removed from the glove box, the alumina pot is attached to a ball mill set in a dry atmosphere, and mechanochemically treated at 120 rpm for 300 hours to vitrify the raw material inorganic composition. rice field. Every 24 hours of mixing, the powder adhering to the inner wall of the pot was scraped off in the glove box, and after sealing, milling was continued in a dry atmosphere.
Here, when the pot was opened after performing the mechanochemical treatment for 36 hours, lumps of the inorganic composition adhered to the inner wall of the pot. Therefore, it was necessary to scrape off the clumps of the inorganic composition adhering to the inner wall of the pot every 24 hours.
Then, put an alumina pot in the glove box, separate the obtained powder from the ZrO ₂ balls, transfer it from the alumina pot to a carbon crucible, and bake it in an oven installed in the glove box at 270 ° C for 2 hours. Annealing treatment was performed to obtain a sulfide-based inorganic solid electrolyte material. Each evaluation was performed on the obtained sulfide-based inorganic solid electrolyte material. Table 1 shows the results obtained.

The sulfide-based inorganic solid electrolyte material of the example was more suppressed in deterioration of lithium ion conductivity than the sulfide-based inorganic solid electrolyte material of the comparative example even when exposed to the air. That is, it can be understood that the sulfide-based inorganic solid electrolyte materials of the examples can suppress a decrease in lithium ion conductivity when exposed to the air.
Here, the X-ray diffraction spectra of the sulfide-based inorganic solid electrolyte materials obtained in Examples and Comparative Examples are shown in FIGS. 2 and 3, respectively.

100 Lithium ion battery 101 Positive electrode active material layer 103 Negative electrode active material layer 105 Current collector 110 Positive electrode 120 Electrolyte layer 130 Negative electrode

Claims (18)

A sulfide-based inorganic solid electrolyte material having lithium ion conductivity and containing Li, P and S as constituent elements,
A sulfide-based inorganic solid electrolyte material that generates 20 ppm or less of hydrogen sulfide, as measured by the following method.
(Method)
The sulfide-based inorganic solid electrolyte material is placed in a closed glass container that has been replaced with argon gas, and then water is dropped from the top of the closed glass container onto the sulfide-based inorganic solid electrolyte material for 5 minutes. Afterwards, the amount of hydrogen sulfide gas generated in the closed glass container is measured. In the sulfide-based inorganic solid electrolyte material according to claim 1,
In the spectrum obtained by X-ray diffraction using CuKα rays as a radiation source, the position of the diffraction angle 2θ = 17.2 ± 0.5 °, the position of the diffraction angle 2θ = 25.6 ± 0.5 ° and the diffraction angle 2θ = A sulfide-based inorganic solid electrolyte material having diffraction peaks at positions of 29.2±0.8°. In the sulfide-based inorganic solid electrolyte material according to claim 2,
In the spectrum obtained by X-ray diffraction using CuKα rays as a radiation source, the maximum diffraction intensity at the position of diffraction angle 2θ = 35.0 ± 0.1 ° was taken as the background intensity _IA , and the diffraction angle 2θ = 17.2 ± A sulfide-based inorganic solid electrolyte material having a value of _IB / _IA of 2.0 or more, where _IB is the maximum diffraction intensity of a diffraction peak present at a position of 0.5°. In the sulfide-based inorganic solid electrolyte material according to claim 2 or 3,
In the spectrum obtained by X-ray diffraction using CuKα rays as a radiation source, the maximum diffraction intensity at the position of diffraction angle 2θ = 35.0 ± 0.1 ° is defined as background intensity _IA , and diffraction angle 2θ = 25.6 ± A sulfide-based inorganic solid electrolyte material having a value of _IC / _IA of 2.0 or more, where _IC is the maximum diffraction intensity of a diffraction peak present at a position of 0.5°. In the sulfide-based inorganic solid electrolyte material according to any one of claims 2 to 4,
In the spectrum obtained by X-ray diffraction using CuKα rays as a radiation source, the maximum diffraction intensity at the position of diffraction angle 2θ = 35.0 ± 0.1 ° was taken as background intensity _IA , and diffraction angle 2θ = 29.2 ± A sulfide-based inorganic solid electrolyte material having a value of _ID / _IA of 2.0 or more, where _ID is the maximum diffraction intensity of a diffraction peak present at a position of 0.8°. In the sulfide-based inorganic solid electrolyte material according to any one of claims 2 to 5,
A spectrum obtained by X-ray diffraction using CuKα rays as a radiation source further has a diffraction peak at a diffraction angle 2θ = 26.6 ± 0.4 °,
The maximum diffraction intensity at the diffraction angle 2θ=35.0±0.1° is defined as the background intensity _IA , and the maximum diffraction intensity of the diffraction peak at the diffraction angle 2θ=26.6±0.4° is A sulfide-based inorganic solid electrolyte material having a value of _IE / _IA of 2.2 or more when _IE . In the sulfide-based inorganic solid electrolyte material according to any one of claims 1 to 6,
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 5.0 or less, and the S content to the P content A sulfide-based inorganic solid electrolyte material having a molar ratio S/P of 2.0 or more and 6.0 or less. In the sulfide-based inorganic solid electrolyte material according to any one of claims 1 to 7,
The lithium ion conductivity of the sulfide-based inorganic solid electrolyte material is 2.2×10 ⁻⁴ S cm ⁻ according to the AC impedance method under the measurement conditions of 27.0° C., an applied voltage of 10 mV, and a measurement frequency range of 0.1 Hz to 7 MHz. ¹ or more sulfide-based inorganic solid electrolyte material. In the sulfide-based inorganic solid electrolyte material according to any one of claims 1 to 8,
A sulfide-based inorganic solid electrolyte material having a maximum oxidative decomposition current of 0.50 μA or less, measured under conditions of a temperature of 25° C., a sweep voltage range of 0 to 5 V, and a voltage sweep rate of 5 mV/sec. Solid electrolyte material. In the sulfide-based inorganic solid electrolyte material according to any one of claims 1 to 9,
A sulfide-based inorganic solid electrolyte material in a glass-ceramic state. In the sulfide-based inorganic solid electrolyte material according to any one of claims 1 to 10,
The shape of the sulfide-based inorganic solid electrolyte material is particulate,
A sulfide-based inorganic solid electrolyte material, wherein the average particle diameter _d50 of the particulate sulfide-based inorganic solid electrolyte material is 1 μm or more and 100 μm or less in a weight-based particle size distribution measured by a laser diffraction scattering particle size distribution measurement method. In the sulfide-based inorganic solid electrolyte material according to any one of claims 1 to 11,
A sulfide-based inorganic solid electrolyte material used in lithium-ion batteries. A solid electrolyte comprising the sulfide-based inorganic solid electrolyte material according to any one of claims 1 to 12. A solid electrolyte membrane comprising the solid electrolyte according to claim 13 as a main component. In the solid electrolyte membrane according to claim 14,
A solid electrolyte membrane, which is a pressure-molded body of the particulate solid electrolyte. In the solid electrolyte membrane according to claim 14 or 15,
A solid electrolyte membrane, wherein the content of the binder resin in the solid electrolyte membrane is less than 0.5% by mass when the entire solid electrolyte membrane is taken as 100% by mass. In the solid electrolyte membrane according to any one of claims 14 to 16,
A solid electrolyte membrane, wherein the content of the sulfide-based inorganic solid electrolyte material in the solid electrolyte membrane is 50% by mass or more when the entire solid electrolyte membrane is taken as 100% by mass. A lithium ion battery comprising a positive electrode including a positive electrode active material layer, an electrolyte layer, and a negative electrode including a negative electrode active material layer,
A lithium ion battery in which at least one of the positive electrode active material layer, the electrolyte layer and the negative electrode active material layer comprises the sulfide-based inorganic solid electrolyte material according to any one of claims 1 to 12.

Images