JP6933442B2 - Inorganic solid electrolyte material, solid electrolyte sheet and all-solid-state lithium-ion battery - Google Patents

Description

The present invention relates to inorganic solid electrolyte materials, solid electrolyte sheets and all-solid-state lithium-ion batteries.

Lithium-ion batteries are generally used as a power source for small portable devices such as mobile phones and laptop 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.

Currently commercially available lithium ion batteries use an electrolytic solution containing a flammable organic solvent. 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 and the battery is completely solidified does not use a flammable organic solvent in the battery, and thus is a safety device. It is considered that the manufacturing cost and productivity are excellent because of the simplification of the battery.

In such an all-solid-state lithium-ion battery, a solid electrolyte sheet mainly containing a solid electrolyte material is used as the solid electrolyte layer. The following Patent Document 1 describes an example of such a solid electrolyte sheet.

According to Patent Document 1 (Japanese Unexamined Patent Publication No. 2008-124011), a crystalline solid electrolyte sheet is produced in which a glass-like lithium ion conductive solid electrolyte is formed into a sheet and then heat-treated, or is formed into a sheet and then heat-treated. The method is described.

Japanese Unexamined Patent Publication No. 2008-124011

According to the studies by the present inventors, it has become clear that the battery characteristics of the obtained all-solid-state lithium-ion battery are not yet satisfactory with respect to the solid electrolyte sheet as described in Patent Document 1.

The present invention has been made in view of the above circumstances, and provides an inorganic solid electrolyte material and a solid electrolyte sheet capable of realizing an all-solid-state lithium-ion battery having excellent battery characteristics, and an all-solid-state lithium-ion battery having excellent battery characteristics. It is a thing.

The present inventors have diligently studied to achieve the above-mentioned problems. As a result, they have found that an all-solid-state lithium-ion battery having excellent battery characteristics can be obtained by highly controlling the elastic modulus of the inorganic solid electrolyte material or the solid electrolyte sheet, and have reached the present invention.

That is, according to the present invention.
An inorganic solid electrolyte material having lithium ion conductivity.
The elastic modulus of the pressure-molded article obtained by press-molding the inorganic solid electrolyte material at 500 MPa for 10 minutes by the nanointention method is 0.5 × 10 ⁹ Pa or more and 1.0 × 10 ¹² Pa or less.
The inorganic solid electrolyte material contains a sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements.
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 above S with respect to the P content. The molar ratio (S / P) of the content is 1.0 or more and 10.0 or less.
The inorganic solid electrolyte material is in the form of particles and is in the form of particles.
In weight particle size distribution by a laser diffraction scattering particle size distribution measuring method, the ratio _(d 90 _/ d ₅₀₎ of particle diameter _{d 90} for the mean particle size _{d 50} of the inorganic solid electrolyte material Ri der 2.2 or less,
An inorganic solid electrolyte material having an average particle size d ₅₀ of 2 μm or more and 40 μm or less is provided.

Further, according to the present invention.
A solid electrolyte sheet containing the above-mentioned inorganic solid electrolyte material as a main component is provided.

Further, according to the present invention.
A solid electrolyte sheet containing an inorganic solid electrolyte material having lithium ion conductivity.
The elastic modulus by the nanointention method is 0.5 × 10 ⁹ Pa or more and 1.0 × 10 ¹² Pa or less.
The inorganic solid electrolyte material contains a sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements.
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 above S with respect to the P content. The molar ratio (S / P) of the content is 1.0 or more and 10.0 or less.
It is a pressure-molded article of the inorganic solid electrolyte material in the form of particles.
In weight particle size distribution by a laser diffraction scattering particle size distribution measuring method, the ratio _(d 90 _/ d ₅₀₎ of particle diameter _{d 90} for the mean particle size _{d 50} of the inorganic solid electrolyte material Ri der 2.2 or less,
A solid electrolyte sheet having an average particle size d ₅₀ of 2 μm or more and 40 μm or less is provided.

Further, according to the present invention
An all-solid-state lithium-ion battery in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated in this order.
An all-solid-state lithium-ion battery in which the solid electrolyte layer is composed of the solid electrolyte sheet is provided.

According to the present invention, it is possible to provide an inorganic solid electrolyte material and a solid electrolyte sheet capable of realizing an all-solid-state lithium-ion battery having excellent battery characteristics, and an all-solid-state lithium-ion battery having excellent battery characteristics.

It is sectional drawing which shows typically an example of the structure of the all-solid-state lithium ion battery of embodiment which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The figure is a schematic view and does not match the actual dimensional ratio. Unless otherwise specified, "A to B" in the numerical range represent A or more and B or less.

[Inorganic solid electrolyte material]
First, the inorganic solid electrolyte material according to the present embodiment will be described.
The inorganic solid electrolyte material according to the present embodiment is an inorganic solid electrolyte material having lithium ion conductivity, and the nanoinstance of the pressure-formed body obtained by press-molding the inorganic solid electrolyte material at 500 MPa for 10 minutes. The elastic modulus according to the method is 0.5 × 10 ⁹ Pa or more, preferably 1.0 × 10 ⁹ Pa or more, more preferably 2.0 × 10 ⁹ Pa or more, still more preferably 5.0 ×. It is 10 ⁹ Pa or more, more preferably 1.0 × 10 ¹⁰ Pa or more, and particularly preferably 2.0 × 10 ¹⁰ Pa or more.
In the inorganic solid electrolyte material according to the present embodiment, the strength of the obtained solid electrolyte sheet can be improved by setting the elastic modulus by the nanointention method to the above lower limit value or more, and the solid is formed by the volume change of the electrode caused by charging and discharging. It is possible to prevent the electrolyte layer from being cracked and the positive electrode and the negative electrode from coming into contact with each other. As a result, the battery characteristics of the all-solid-state lithium-ion battery can be improved.
Further, the upper limit of the elastic modulus of the inorganic solid electrolyte material according to the present embodiment by the nanointention method is not particularly limited, but from the viewpoint of improving the stress relaxation force of the obtained solid electrolyte sheet, for example, 1.0 × 10 ¹² It is Pa or less, preferably 1.0 × 10 ¹¹ Pa or less, more preferably 8.0 × 10 ¹⁰ Pa or less, and further preferably 5.0 × 10 ¹⁰ Pa or less. As a result, cracks in the solid electrolyte layer due to the volume change of the electrodes caused by charging and discharging can be further suppressed, and as a result, the battery characteristics of the all-solid-state lithium ion battery can be further improved.
In the present embodiment, the battery characteristics of the all-solid-state lithium-ion battery refer to, for example, discharge capacity density, output characteristics, cycle characteristics, and the like.

According to the study by the present inventors, the elastic modulus of the inorganic solid electrolyte material or the solid electrolyte sheet is highly controlled, that is, the elastic modulus of the inorganic solid electrolyte material by the nanointention method and the solid electrolyte sheet described later. We have found that an all-solid-state lithium-ion battery having excellent battery characteristics can be obtained by setting the elastic modulus by the nanointention method within a specific range, and have reached the present invention.
The reason why an all-solid-state lithium-ion battery having excellent battery characteristics can be obtained by using the inorganic solid electrolyte material or the solid electrolyte sheet according to the present embodiment is not clear, but the following reasons can be considered.
First, if the elastic modulus of the inorganic solid electrolyte material or the solid electrolyte sheet is low, it is considered that cracks are likely to occur in the solid electrolyte layer due to the volume change of the electrode caused by charging and discharging. When this crack occurs, the positive electrode and the negative electrode come into contact with each other to cause a short circuit or the like, and the battery characteristics of the obtained all-solid-state lithium-ion battery deteriorate.
On the other hand, the inorganic solid electrolyte material and the solid electrolyte sheet according to the present embodiment have an elastic modulus of a specific value or more and are excellent in strength. Therefore, it is considered that cracks are less likely to occur in the solid electrolyte layer during charging and discharging. For the above reasons, it is considered that the use of the inorganic solid electrolyte material or the solid electrolyte sheet according to the present embodiment can suppress the deterioration of the battery characteristics of the obtained all-solid-state lithium ion battery.
From the above, according to the inorganic solid electrolyte material and the solid electrolyte sheet according to the present embodiment, an all-solid-state lithium ion battery having excellent battery characteristics can be realized.

Here, the elastic modulus of the pressure-molded article and the solid electrolyte sheet described later by the nanointention method can be performed according to the following conditions.
As a measuring device, for example, a dynamic microhardness meter (DUH-W201) manufactured by Shimadzu Corporation is used, and a triangular pyramid indenter (edge angle 115 °) is used as an indenter, and a constant test force P (mN) is used. The elastic modulus E can be measured from the load-unloading test (test condition on the device: MODE2). At this time, the elastic modulus E is obtained by E = σ / ε. σ is the force per unit area (Pa), and ε is the rate of change in length (ΔL / L ₀ ). The test conditions can be, for example, a test force of 50 mN, a load speed of 4.412993 mN / sec, a load holding time of 2 seconds, and the number of tests of 3 times. The average value of three tests can be used as the elastic modulus by the nanointention method.

In the present embodiment, for example, by appropriately selecting the type of the inorganic solid electrolyte material, the particle size distribution of the inorganic solid electrolyte material, etc., the nanointention method of the inorganic solid electrolyte material or the solid electrolyte sheet according to the present embodiment is applied. It is possible to control the elastic modulus within a desired range. Among these, for example, the ratio of Li / P and S / P in the inorganic solid electrolyte material described later, the particle size distribution of the inorganic solid electrolyte material (d ₉₀ / d ₅₀ ), and the like are the inorganic solid electrolyte materials according to the present embodiment. It can be mentioned as an element for setting the elastic modulus of the solid electrolyte sheet by the nanoinorganic tension method in a desired numerical range.

The inorganic solid electrolyte material according to the present embodiment is not particularly limited as long as it has lithium ion conductivity, and is, for example, a sulfide-based inorganic solid electrolyte material, an oxide-based inorganic solid electrolyte material, and other lithium-based inorganic materials. Examples include solid electrolyte materials. Among these, a sulfide-based inorganic solid electrolyte material is preferable. As a result, the interfacial resistance between the inorganic solid electrolyte materials is further reduced, and a solid electrolyte sheet having more excellent lithium ion conductivity can be obtained.

Examples of the sulfide-based inorganic solid electrolyte material include Li ₂ SP ₂ S ₅ material, Li ₂ S-SiS ₂ material, Li ₂ S-GeS ₂ material, Li ₂ S-Al ₂ S ₃ material, and 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 Examples thereof include S _{5- SiS 2} material, Li ₂ S-SnS _2- P ₂ S _5- SiS ₂ material and the like. _{Among these, the Li 2} SP ₂ S ₅ material is preferable because it has excellent lithium ion conductivity and the manufacturing method is simple.
These may be used individually by 1 type, or may be used in combination of 2 or more type. _{Among these, the Li 2} SP ₂ S ₅ material is preferable because it has excellent lithium ion conductivity and stability that does not cause decomposition in a wide voltage range. Here, for example, the Li ₂ SP ₂ S ₅ material means a material obtained by mixing and pulverizing a mixture containing at least Li ₂ S (lithium sulfide) and P ₂ S _{5 by mechanochemical treatment or the like.} do.

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 , and (La _{0.5 + x} Li _{0.5). -3x} ) _{Perovskite type such as TiO 3 and the} like can be mentioned.
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, and LISION. Be done. Further, glass ceramics obtained by precipitating crystals of these inorganic solid electrolytes can also be used as the inorganic solid electrolyte material.

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

Further, in the sulfide-based inorganic solid electrolyte material according to the present 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. It is 0 or less, more preferably 2.0 or more and 5.0 or less, further preferably 3.0 or more and 4.5 or less, and particularly preferably 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, and further. It is preferably 3.0 or more and 5.0 or less, and particularly preferably 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.

Examples of the shape of the inorganic solid electrolyte material include particulate matter. The particulate inorganic solid electrolyte material of the present embodiment is not particularly limited, but the ratio of the particle size d _{90 to the average particle size d 50} of the inorganic solid electrolyte material in the weight-based particle size distribution by the laser diffraction scattering type particle size distribution measurement method ( d ₉₀ / d ₅₀ ) is preferably 2.5 or less, and more preferably 2.2 or less. When d ₉₀ / d ₅₀ is not more than the above upper limit value, the packing density of the inorganic solid electrolyte material is improved and densified, so that the inorganic solid electrolyte material according to the present embodiment and the solid electrolyte sheet according to the present embodiment are formed. The elastic modulus of the nano-inorganic method can be increased.
The average particle size _{d 50} of the particulate inorganic solid electrolyte material of the present embodiment is preferably not 1μm or 40μm or less, more preferably 2μm or more 30μm or less, more preferably 3μm or more 20μm or less.
_{By setting the average particle size d 50} of the inorganic solid electrolyte material within the above range, good handleability can be maintained and the lithium ion conductivity of the solid electrolyte sheet can be further improved.

[Manufacturing method of inorganic solid electrolyte material]
Subsequently, a method for producing the inorganic solid electrolyte material according to the present embodiment will be described.
Hereinafter, a method for producing a sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements will be described as an example.
The sulfide-based inorganic solid electrolyte material containing Li, P, and S according to the present embodiment contains, for example, Li ₂ S and P ₂ S ₅ as raw materials in a specific ratio, and contains Li ₃ N as necessary. Further, it can be obtained by vitrifying the containing mixture A, classifying it, and adjusting the particle size distribution.
Further, the obtained mixture B in a glass state may be heated (also referred to as heat treatment). More specifically, the sulfide-based inorganic solid electrolyte material according to the present embodiment can be obtained by a production method including the following steps (1) and (2). In addition, the method for producing a sulfide-based inorganic solid electrolyte material according to the present embodiment may further include the following step (3).

(1) _{Step of vitrifying the mixture A containing Li 2} S and P ₂ S ₅ in a specific ratio _{and further containing Li 3} N if necessary (2) The obtained mixture B in a glass state is classified. Step of adjusting particle size distribution (3) Step of crystallizing at least a part of the mixture B by heating the mixture B in a glass state Each step will be described below.

<Step of vitrifying mixture A>
First, a _{mixture A containing Li 2} S and P ₂ S ₅ in a specific proportion and, if necessary, _{further Li 3} N is prepared. The mixing ratio of Li ₂ S, P ₂ S ₅ and Li ₃ N is appropriately set by a sulfide-based inorganic solid electrolyte material having a desired composition ratio.
Next, the mixture A is vitrified.
The method for vitrifying the mixture A is not particularly limited, but for example, it can be carried out by a mechanochemical treatment, a melt quenching method, or the like.
Among these, it is preferable to carry out by mechanochemical treatment. This is because the treatment at room temperature is possible and the manufacturing process can be simplified. Further, the mechanochemical treatment may be a dry mechanochemical treatment or a wet mechanochemical treatment.
When the mechanochemical treatment is used, Li ₂ S, P ₂ S ₅ and Li ₃ N can be mixed while being pulverized into fine particles, so that the contact area of _{Li 2} S, P ₂ S ₅ and Li _{3 N is increased.} can do. As a result, _{the reaction of Li 2} S, P ₂ S ₅ and Li ₃ N can be promoted, so that the inorganic solid electrolyte material according to the present embodiment can be obtained even more efficiently.

Here, the mechanochemical treatment is a method of vitrifying a mixture object while applying mechanical energy such as shear force, collision force or centrifugal force. Examples of devices that perform vitrification by mechanochemical treatment include crushers / dispersers such as ball mills, bead mills, vibration mills, turbo mills, mechanofusions, and disc mills. Among these, a ball mill is preferable, and a planetary ball mill is particularly preferable. In a planetary ball mill, the base rotates while the pot rotates on its axis, so that extremely high impact energy can be efficiently generated. Therefore, a desired inorganic solid electrolyte material can be efficiently obtained.

Mixing conditions such as rotation speed, processing time, temperature, reaction pressure, and gravitational acceleration applied to the mixture when vitrifying the mixture A can be appropriately determined depending on the processing amount of the mixture A. In general, the faster the rotation speed, the faster the glass formation rate, and the longer the processing time, the higher the conversion rate to glass. For example, when a general planetary ball mill machine is used, the rotation speed may be several tens to several hundreds rpm, and the processing may be performed for 0.5 hours to 500 hours. Typically, when the X-ray diffraction analysis using CuKα rays as a radiation source, when the diffraction peak of P ₂ S ₅ and Li 3 _N is a raw material disappeared, the mixture A is vitrified, mixtures B It can be judged that it has been obtained.

The inorganic solid electrolyte material of the present embodiment is preferably more amorphous, from the viewpoint of further improving the conductivity of lithium ions.

<Process of classifying and adjusting particle size distribution>
Subsequently, the obtained mixture B in the glass state is classified to adjust the particle size distribution. The classification method is not particularly limited, and a known method such as a sieve can be used. Here, in the step of classifying and adjusting the particle size distribution, it is preferable to adjust the ratio of the particle size d _{90 to the average particle size d 50 of the inorganic solid electrolyte material (d 90} / d ₅₀ ) to 2.5 or less. It is more preferable to adjust it to 2.2 or less.
These classifications are preferably performed in an inert gas atmosphere or a vacuum atmosphere from the viewpoint of preventing contact with moisture in the air.
Further, the step of classifying and adjusting the particle size distribution _{may be performed on the raw materials Li 2} S, P ₂ S ₅ and Li ₃ N before the step (1) above, or may be performed on the raw materials Li 2 S, P 2 S 5 and Li 3 N. ) May be followed by the above mixture B. Further, after the step (3), the mixture B may be subjected to the heat treatment.

<Step of crystallizing at least a part of mixture B>
Subsequently, a step of crystallizing at least a part of the mixture B by heating the obtained mixture B in a glass state will be described.
In the method for producing an inorganic solid electrolyte material according to the present embodiment, at least a part of the mixture B may be crystallized by heating the mixture B in a glass state. By doing so, it is possible to obtain an inorganic solid electrolyte material having further excellent lithium ion conductivity.

The temperature at which the mixture B is heated is preferably in the range of 280 ° C. or higher and 500 ° C. or lower, and more preferably in the range of 280 ° C. or higher and 350 ° C. or lower.
When the temperature at which the mixture B is heated is within the above range, even more excellent lithium ion conductivity can be obtained.

The time for heating the mixture B is not particularly limited as long as the desired inorganic solid electrolyte material can be obtained, but is, for example, in the range of 1 minute or more and 24 hours or less, preferably 0.5. It is more than an hour and less than 3 hours. The heating method is not particularly limited, and examples thereof include a method using a firing furnace. The conditions such as temperature and time for heating can be appropriately adjusted in order to optimize the characteristics of the inorganic solid electrolyte material of the present embodiment.

In order to obtain the inorganic solid electrolyte material according to the present embodiment, it is important to appropriately adjust each of the above steps. However, the method for producing the inorganic solid electrolyte material according to the present embodiment is not limited to the above method, and the inorganic solid electrolyte material according to the present embodiment can be obtained by appropriately adjusting various conditions. Can be done.

[Solid electrolyte sheet]
Next, the solid electrolyte sheet according to this embodiment will be described.
The solid electrolyte sheet according to the present embodiment is a solid electrolyte sheet containing the above-mentioned inorganic solid electrolyte material according to the present embodiment as a main component, or a solid electrolyte sheet containing an inorganic solid electrolyte material having lithium ion conductivity as a main component. there are, modulus of elasticity as measured by nano-Day tension method is a solid electrolyte sheet is 0.5 × 10 9 ^Pa or more.
Here, examples of the inorganic solid electrolyte material having lithium ion conductivity include the above-mentioned inorganic solid electrolyte material according to the present embodiment.

The elastic modulus of the solid electrolyte sheet according to the present embodiment by the nanointention method is preferably 1.0 × 10 ⁹ Pa or more, more preferably 2.0 × 10 ⁹ Pa or more, and further preferably 5. It is 0 × 10 ⁹ Pa or more, more preferably 1.0 × 10 ¹⁰ Pa or more, and particularly preferably 2.0 × 10 ¹⁰ Pa or more.
In the solid electrolyte sheet according to the present embodiment, the strength of the obtained solid electrolyte layer can be improved by setting the elastic modulus by the nanointention method to the above lower limit value or more, and the solid electrolyte is caused by the volume change of the electrode caused by charging and discharging. It is possible to prevent the layer from being cracked and the positive electrode and the negative electrode from coming into contact with each other. As a result, the battery characteristics of the all-solid-state lithium-ion battery can be improved.
The upper limit of the elastic modulus of the solid electrolyte sheet according to the present embodiment by the nanointention method is not particularly limited, but from the viewpoint of improving the stress relaxation force of the obtained solid electrolyte sheet, for example, 1.0 × 10 ¹² Pa. It is less than or equal to, preferably 1.0 × 10 ¹¹ Pa or less, more preferably 8.0 × 10 ¹⁰ Pa or less, and further preferably 5.0 × 10 ¹⁰ Pa or less. As a result, cracks in the solid electrolyte layer due to the volume change of the electrodes caused by charging and discharging can be further suppressed, and as a result, the battery characteristics of the all-solid-state lithium ion battery can be further improved.

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

The average thickness of the solid electrolyte sheet 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 further preferably 20 μm or more and 100 μm or less. When the average thickness of the solid electrolyte sheet is at least the above lower limit value, the lack of the inorganic solid electrolyte material and the cracking on the surface of the solid electrolyte sheet can be further suppressed. Further, when the average thickness of the solid electrolyte sheet is not more than the upper limit value, the impedance of the solid electrolyte sheet can be further lowered. As a result, the battery characteristics of the obtained all-solid-state lithium-ion battery can be further improved.

The solid electrolyte sheet according to the present embodiment is preferably a pressure-molded body of a particulate inorganic solid electrolyte material. That is, it is preferable to pressurize the particulate inorganic solid electrolyte material to obtain a solid electrolyte sheet having a certain strength due to the anchor effect between the inorganic solid electrolyte materials.
By forming the pressure-molded body, the inorganic solid electrolyte materials are bonded to each other, and the strength of the obtained solid electrolyte sheet is further increased. As a result, the lack of the inorganic solid electrolyte material and the cracking on the surface of the inorganic solid electrolyte material can be further suppressed.

The content of the inorganic solid electrolyte material in the solid electrolyte sheet according to the present embodiment is preferably 98% by mass or more, more preferably 99% by mass or more, still more preferably, when the whole solid electrolyte sheet is 100% by mass. Is 100% by mass. As a result, the contact property between the inorganic solid electrolyte materials can be improved, and the interfacial contact resistance of the solid electrolyte sheet can be reduced. As a result, the lithium ion conductivity of the solid electrolyte sheet can be further improved. Then, by using such a solid electrolyte sheet having excellent lithium ion conductivity, the battery characteristics of the obtained all-solid-state lithium ion battery can be further improved.

The planar shape of the solid electrolyte sheet is not particularly limited and can be appropriately selected according to the shape of the electrode layer or the current collector layer, but can be, for example, a rectangle.

Further, the solid electrolyte sheet according to the present embodiment may contain a binder resin, but the content of the binder resin is preferably less than 0.5% by mass when the whole solid electrolyte sheet is 100% by mass. It is more preferably 0.1% by mass or less, further preferably 0.05% by mass or less, and even more preferably 0.01% by mass or less. Further, it is more preferable that the solid electrolyte sheet according to the present embodiment substantially does not contain a binder resin, and most preferably it does not contain a binder resin.
As a result, the contact property between the inorganic solid electrolyte materials can be improved, and the interfacial contact resistance of the solid electrolyte sheet can be reduced. As a result, the lithium ion conductivity of the solid electrolyte sheet can be further improved. Then, by using such a solid electrolyte sheet having excellent lithium ion conductivity, the battery characteristics of the obtained all-solid-state lithium ion battery can be improved.
In addition, "substantially free of binder resin" means that the binder resin may be contained to the extent that the effect of the present invention is not impaired. When the adhesive resin layer is provided between the solid electrolyte layer and the positive electrode layer or the negative electrode layer, the adhesive resin derived from the adhesive resin layer existing near the interface between the solid electrolyte layer and the adhesive resin layer is ". It is removed from the "binder resin in the solid electrolyte sheet".

The binder resin refers to a binder generally used in lithium ion batteries for binding inorganic solid electrolyte materials, for example, polyvinyl alcohol, polyacrylic acid, carboxymethyl cellulose, and polytetrafluoro. Examples thereof include ethylene, polyvinylidene fluoride, styrene / butadiene rubber, and polyimide.

[Manufacturing method of solid electrolyte sheet]
Next, a method for producing the solid electrolyte sheet according to the present embodiment will be described.
The solid electrolyte sheet according to the present embodiment can be produced, for example, by a production method including the following steps (A), (B) and (C).
(A) Step of filling the voids of the porous body with the inorganic solid electrolyte material according to the present embodiment in the form of particles (B) The inorganic solid electrolyte material filled in the voids of the porous body is placed on the cavity surface of the mold or the surface of the base material. Step of depositing the inorganic solid electrolyte material in the form of a film on the cavity surface of the mold or on the surface of the base material by sieving it off (C) Step of pressurizing the inorganic solid electrolyte material deposited in the form of a film The following steps Will be described in detail.

First, (A) a particulate inorganic solid electrolyte material is filled in the voids of the porous body. The method for filling the voids of the porous body with the particulate inorganic solid electrolyte material is not particularly limited, and for example, the particulate inorganic solid electrolyte material is directly supplied into the voids of the porous body in the air or in an inert atmosphere. Examples thereof include a method in which a particulate inorganic solid electrolyte material is dispersed in a solvent to form a slurry, then the slurry is applied onto a porous body, the slurry is allowed to permeate into the voids, and then the solvent is dried. Be done.

As a method of directly supplying the particulate inorganic solid electrolyte material into the voids of the porous body in the air or in an inert atmosphere, the inorganic solid electrolyte material is powder-coated on the porous body, and the inorganic solid electrolyte material is powder-coated on the porous body, and the porous body is squeezed. Examples thereof include a method of filling the voids with the inorganic solid electrolyte material while removing the excess inorganic solid electrolyte material.
As a method for applying the slurry, generally known methods such as a doctor blade coating method, a dip coating method, a spray coating method, and a bar coater coating method can be used.
By these methods, the inorganic solid electrolyte material can be continuously filled in the voids of the porous body.

Here, the porous body is capable of filling the voids with the inorganic solid electrolyte material.
The shape of the porous body is not particularly limited, but from the viewpoint of ease of handling, it is preferably in the form of a sheet.
Examples of the form of the porous body include one or more selected from woven fabrics, non-woven fabrics, mesh cloths, porous films, expanding sheets, punching sheets and the like.

Next, (B) the inorganic solid electrolyte material filled in the voids of the porous body is sieved onto the cavity surface of the mold or the surface of the base material, so that the inorganic solid is formed on the cavity surface of the mold or the surface of the base material. The electrolyte material is deposited in a film form. Here, the inorganic solid electrolyte material filled in the voids of the porous body is sieved onto the cavity surface of the mold or the surface of the base material until the desired thickness is obtained.
Since the inorganic solid electrolyte material is screened off little by little by the openings of the porous body, it can be deposited in a film shape with a uniform thickness on the cavity surface of the mold or on the surface of the base material.

As a method of sieving the inorganic solid electrolyte material onto the cavity surface of the mold or the surface of the base material, for example, the inorganic solid electrolyte material filled in the voids of the porous body is placed in the cavity of the mold by vibrating the porous body. Examples thereof include a method of sieving off on the surface or the surface of the base material.

Further, in the step (B), the step of vibrating the inorganic solid electrolyte material deposited in the form of a film to cause the particulate inorganic solid electrolyte material to flow and densify the inorganic solid electrolyte material deposited in the form of a film. Further may be included. The thickness of the solid electrolyte sheet thus obtained can be made even more uniform. Examples of the method of vibrating include vibration with a small amplitude such as ultrasonic vibration and light impact by a hammer.

Examples of the base material include a positive electrode layer, a negative electrode layer, a metal foil, a plastic film, carbon and the like.

Next, (C) the inorganic solid electrolyte material deposited in the form of a film is pressurized. As a result, the solid electrolyte sheet has a certain strength due to the anchor effect between the inorganic solid electrolyte materials. Here, when the particulate inorganic solid electrolyte material is deposited on the surface of the base material, the base material may be pressurized in a laminated state, or the base material may be peeled off and then pressurized.
When pressure is applied, the inorganic solid electrolyte materials are bonded to each other, and the strength of the obtained solid electrolyte sheet is further increased. As a result, the lack of the inorganic solid electrolyte material and the cracking on the surface of the inorganic solid electrolyte material can be further suppressed.
The method of pressurizing the above-mentioned inorganic solid electrolyte material is not particularly limited. For example, when the inorganic solid electrolyte material is deposited on the cavity surface of the die, a press by a die and a stamping die, or a particulate inorganic solid electrolyte material is applied. When deposited on the surface of the base material, a press using a die and a pressing die, a roll press, a flat plate press, or the like can be used.
The pressure for pressurizing the inorganic solid electrolyte material is, for example, 10 MPa or more and 500 MPa or less.

Further, if necessary, the inorganic solid electrolyte material deposited in the form of a film may be pressurized and heated. When heat and pressure are applied, the inorganic solid electrolyte materials are fused and bonded to each other, and the strength of the obtained solid electrolyte sheet is further increased. As a result, the lack of the inorganic solid electrolyte material and the cracking on the surface of the inorganic solid electrolyte material can be further suppressed.
The temperature at which the inorganic solid electrolyte material is heated is, for example, 40 ° C. or higher and 500 ° C. or lower.

[All-solid-state lithium-ion battery]
Next, the all-solid-state lithium-ion battery 200 according to the present embodiment will be described. FIG. 1 is a cross-sectional view schematically showing an example of the structure of the all-solid-state lithium-ion battery 200 according to the embodiment of the present invention. The all-solid-state lithium-ion battery 200 according to the present embodiment is a lithium-ion secondary battery, but may be a lithium-ion primary battery.

In the all-solid-state lithium-ion battery 200 according to the present embodiment, the positive electrode layer 210, the solid electrolyte layer 220, and the negative electrode layer 230 are laminated in this order. The solid electrolyte layer 220 is composed of the solid electrolyte sheet according to the present embodiment.
Further, the all-solid-state lithium ion battery 200 according to the embodiment is a bipolar lithium ion battery by laminating two or more unit cells composed of a positive electrode layer 210, a solid electrolyte layer 220, and a negative electrode layer 230. It can also be.
The shape of the all-solid-state lithium-ion battery 200 is not particularly limited, and examples thereof include a cylindrical type, a coin type, a square type, a film type, and any other shape.

The all-solid-state lithium-ion battery 200 according to the present embodiment is manufactured according to a generally known method. For example, it is produced by forming a stack of a positive electrode layer 210, a solid electrolyte layer 220, and a negative electrode layer 230 into a cylindrical shape, a coin shape, a square shape, a film shape, or any other shape.

The positive electrode layer 210 is not particularly limited, and a positive electrode generally used for an all-solid-state lithium ion battery can be used. The positive electrode layer 210 is not particularly limited, but can be manufactured according to a generally known method. For example, it can be obtained by forming a positive electrode active material layer containing a positive electrode active material on a current collector such as an aluminum foil.
The thickness and density of the positive electrode active material layer are appropriately determined according to the intended use of the battery and the like, and are not particularly limited, and can be set according to generally known information.

The positive electrode active material layer contains a positive electrode active material as an essential component.
The positive electrode active material is not particularly limited, and a generally known positive electrode active material that can be used for the positive electrode layer of the all-solid-state lithium ion battery 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 ), olivine type lithium phosphorus oxide (LiFePO ₄ ) and other composite oxides; _{molecule; Li 2 S, CuS, Li} -CuS _{compounds, TiS 2, FeS, MoS 2} , Li-MoS compounds, Li-TiS compound, sulfide-based positive active such as Li-V-S compound Substances; acetylene black impregnated with sulfur, porous carbon impregnated with sulfur, materials using sulfur as an active material such as a mixed powder of sulfur and carbon; and the like can be used. These positive electrode active materials may be used alone or in combination of two or more.
Among these, a sulfide-based positive electrode active material is preferable from the viewpoint of having a higher discharge capacity density and being superior in cycle characteristics, and Li-Mo-S compound, Li-Ti-S compound, and Li-VS. More preferably, one or more selected from the compounds.

Here, the Li-Mo-S compound contains Li, Mo, and S as constituent elements, and is usually obtained by mixing and pulverizing molybdenum sulfide and lithium sulfide, which are raw materials, by mechanochemical treatment or the like. be able to.
Further, the Li-Ti-S compound contains Li, Ti, and S as constituent elements, and is usually obtained by mixing and pulverizing titanium sulfide and lithium sulfide, which are raw materials, by mechanochemical treatment or the like. Can be done.
The Li-VS compound contains Li, V, and S as constituent elements, and can be obtained by mixing and pulverizing vanadium sulfide and lithium sulfide, which are usually raw materials, by mechanochemical treatment or the like. ..

The positive electrode active material layer is not particularly limited, but may contain one or more materials selected from, for example, a solid electrolyte material, a binder, a conductive auxiliary agent, and the like as components other than the positive electrode active material.
The blending ratio of various materials in the positive electrode active material layer is appropriately determined according to the intended use of the battery and the like, and is not particularly limited, and can be set according to generally known information.

The negative electrode layer 230 is not particularly limited, and those generally used for all-solid-state lithium ion batteries can be used. The negative electrode layer 230 is not particularly limited, but can be manufactured according to a generally known method. For example, it can be obtained by forming a negative electrode active material layer containing a negative electrode active material on a current collector such as copper.
The thickness and density of the negative electrode active material layer are appropriately determined according to the intended use of the battery and the like, and are not particularly limited, and can be set according to generally known information.

The negative electrode active material layer contains a negative electrode active material as an essential component.
The negative electrode active material is not particularly limited, and a generally known negative electrode active material that can be used for the negative electrode layer of the all-solid-state lithium ion battery can be used. For example, carbonaceous materials such as natural graphite, artificial graphite, resin charcoal, carbon fiber, activated charcoal, hard carbon, soft carbon; tin, tin alloy, silicon, silicon alloy, gallium, gallium alloy, indium, indium alloy, aluminum, aluminum. Metal-based materials mainly composed of alloys and the like; conductive polymers such as polyacene, polyacetylene and polypyrrole; metallic lithium; lithium titanium composite oxide (for example, Li ₄ Ti ₅ O ₁₂ ) and the like can be mentioned. These negative electrode active materials may be used alone or in combination of two or more.

The negative electrode active material layer is not particularly limited, but may contain one or more materials selected from, for example, a solid electrolyte material, a binder, a conductive auxiliary agent, and the like as components other than the negative electrode active material.
The blending ratio of various materials in the negative electrode active material layer is appropriately determined according to the intended use of the battery and the like, and is not particularly limited, and can be set according to generally known information.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted.
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the range in which the object of the present invention can be achieved are included in the present invention.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

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

(1) ICP emission spectroscopic analysis Using an ICP emission spectrophotometer (SPS3000 manufactured by Seiko Instruments), the mass% of each element in the solid electrolyte material and the positive electrode active material was measured by ICP emission spectroscopic analysis. Each was obtained, and based on that, the molar ratio of each element was calculated.

(2) Particle Size Distribution Using a laser diffraction scattering type particle size distribution measuring device (Mastersizer 3000 manufactured by Malvern Co., Ltd.), the particle size distribution of the inorganic solid electrolyte material used in Examples and Comparative Examples was measured by a laser diffraction method. From the measurement results, for the inorganic solid electrolyte material, the 50% cumulative particle size (D ₅₀ , average particle size) in the weight-based cumulative distribution and the 90% cumulative particle size (D ₉₀ ) in the weight-based cumulative distribution are determined. I asked.

(3) Measurement of elastic modulus by nanointention method In a stainless steel glove box filled with purified argon gas, 200 mg of the inorganic solid electrolyte material obtained in Examples and Comparative Examples was placed in a press jig having a diameter of 14 mm. Press molding was performed at 500 MPa for 10 minutes. Then, the obtained circular pellet (pressure molded product) was placed in a closed container.
A dynamic microhardness meter (DUH-W201) manufactured by Shimadzu Corporation was used as a measuring device, and a triangular pyramid indenter (interridge angle 115 °) was used as an indenter. The dynamic ultra-micro hardness tester was placed in a simple laminated glove box in advance and dried while introducing purified argon.
Take out the circular pellets in the airtight container from the stainless steel glove box, set them in the dynamic ultra-micro hardness tester in the simple glove box, test force 50 mN, load speed 4.412993 mN / sec, load holding time 2 seconds, The load-unloading test was performed under the test conditions of 3 times.
Here, the elastic modulus E can be obtained from the load-unloading test (test condition on the apparatus: MODE2) with a constant test force P (mN). At this time, the elastic modulus E is obtained by E = σ / ε. σ is the force per unit area (Pa), and ε is the rate of change in length (ΔL / L ₀ ). The average value of 3 tests was taken as the elastic modulus by the nanointention method.

(4) Evaluation of battery characteristics Conductive copper foil conductive tape (8313 0.03 manufactured by Teraoka Mfg. Co., Ltd., external dimensions: 25.0 mm x 25.0 mm, thickness: 30 μm, copper foil: 0.009 mm, conductive acrylic adhesive layer : 0.021 mm, graphite (CGC-20, 8 mg manufactured by Nippon Graphite Industry Co., Ltd.) adhered to the pressure-sensitive adhesive layer surface), negative electrode active material layer (indium foil, manufactured by Niraco Co., Ltd., 23.0 mm × 23.0 mm, average thickness: 20 μm), solid electrolyte sheet obtained in Examples and Comparative Examples, positive electrode active material layer (Li ₁₄ MoS ₉ : Ketjen Black (KB): Li ₁₁ P ₃ S ₁₂ = 1: 0.5: 1.2 ( Mass ratio), average thickness: 30 μm), conductive copper foil conductive tape (Teraoka Mfg. Co., Ltd. 8313 0.03, external dimensions: 25.0 mm × 25.0 mm, thickness: 30 μm, copper foil: 0.009 mm, conductive acrylic Adhesive layer: 0.021 mm, Ketjen Black (325 mesh manufactured by Lion Co., Ltd., 0.1 mg) was adhered to the surface of the adhesive layer) in this order. Next, the obtained laminate was pressurized at 320 MPa to prepare a first unit cell. Here, a second unit cell having the same configuration as the first unit cell was produced by the same method as for producing the first unit cell.
Next, an adhesive resin layer (manufactured by Nitto Denko, ultra-thin double-sided tape No. 5600, layer structure: acrylic adhesive layer / PET film base material / acrylic adhesive) having a circular through hole with a diameter of 15 mm formed in the center. A laminate was prepared by laminating the obtained first unit cell and second unit cell via an agent layer, total thickness: 5 μm, outer dimensions: 25.0 mm × 25.0 mm), and the obtained laminate was obtained. Was pressurized at 80 MPa. Next, the obtained laminate was vacuum-laminated with an aluminum laminate film to obtain a bipolar all-solid-state lithium-ion battery.
Next, the obtained all-solid-state lithium-ion battery ^{was charged to a charge termination potential of 4.5 V at a current density of 65 μA / cm 2} at 25 ° C., and then discharged at a current density of 65 μA / cm ^2. Charging and discharging were performed 35 times or more under the condition of discharging to 2.0 V.
Here, when the first discharge capacity is 100%, the 20th discharge capacity is the discharge capacity change rate [%], the one with the discharge capacity change rate of 100% is ⊚, and the discharge capacity change rate is 80% or more. Those with less than 100% were evaluated as ◯, and those with a discharge capacity change rate of less than 80% were evaluated as x.

[2] Materials Next, the materials used in the following Examples and Comparative Examples will be described.

(1) Positive electrode active material (Li ₁₄ MoS ₉ )
In an argon atmosphere _{, add MoS 2} (4.7 mmol manufactured by Wako Pure Chemical Industries, Ltd.) and Li ₂ S (32.5 mmol manufactured by Sigma-Aldrich Japan Co., Ltd.) to a pot made of _{Al 2} O _{3 by weighing.} , Further, a ZrO ₂ ball was put in, and the Al ₂ O ₃ pot was sealed.
Next, the Al ₂ O ₃ pot was placed on a ball mill rotary table and treated at 120 rpm for 4 days to obtain a mixture.
The obtained Li-Mo-S compound was pulverized in a mortar and classified by a sieve having a mesh size of 43 μm to obtain a Li-Mo-S compound.
The molar ratio of Li content to Mo content (Li / Mo) was 14, and the molar ratio of S content to Mo content (S / Mo) was 9.

(2) Porous body As the porous body, nylon mesh cloth (13XX-100 manufactured by Sanjiro Tanaka Shoten Co., Ltd., thickness 105 μm, porosity 36%, opening 100 μm) was used.

<Example 1>
(1) Preparation of Sulfide-based Inorganic Solid Electrolyte Material A Li ₂ SP ₂ S ₅ material, which is a sulfide-based inorganic solid electrolyte material, was prepared by the following procedure.
As raw materials, Li ₂ S (manufactured by Sigma-Aldrich Japan, purity 99.9%) and P ₂ S ₅ (reagent manufactured by Kanto Chemical Co., Inc.) were used. Li ₃ N was prepared by the following procedure.
First, in a glove box with a nitrogen atmosphere, a stainless steel swordsman was used for Li foil (manufactured by Honjo Metal Co., Ltd., purity 99.8%, thickness 0.5 mm) to make many holes of φ1 mm or less. The Li foil began to change to black-purple from the hole portion, and when left as it was at room temperature for 24 hours, all of the Li foil changed to _{black-purple Li 3 N.} Li ₃ N was pulverized in an agate mortar and then sieved with a stainless steel sieve, and a powder of 75 μm or less was recovered and used as a raw material for an inorganic solid electrolyte material.
Next, each raw material was precisely weighed in an argon glove box so that Li ₂ S: P ₂ S ₅ : Li ₃ N = 67.5: 22.5: 10.0 (mol%), and these powders were added. Mix in agate mortar for 20 minutes. Next, 2 g of the mixed powder was weighed and mixed and pulverized at 100 rpm for 1 hour with a planetary ball mill (Fritsch, P-7) together with 500 g of zirconia balls having a diameter of 10 mm. Then, the mixture was mixed and pulverized at 400 rpm for 15 hours to obtain a Li ₂ SP ₂ S _{5 material having a Li 11} P ₃ S _{12 composition.} The obtained _{Li 2} SP ₂ S ₅ material having a composition of _{Li 11} P ₃ S ₁₂ is sieved with a nylon mesh (opening 100 μm) in a stainless glove box filled with purified argon gas. A particulate inorganic solid electrolyte material (Li ₁₁ P ₃ S ₁₂ ) was obtained. The press molding in the measurement of the elastic modulus by the nanointention method described above was performed in the stainless steel glove box without taking out the inorganic solid electrolyte material from the stainless steel glove box. Each evaluation was performed on the obtained particulate inorganic solid electrolyte material (Li ₁₁ P ₃ S _12). The results obtained are shown in Table 1.

(2) Preparation of solid electrolyte sheet A polyethylene terephthalate (PET) plate is attached to one surface of a nylon mesh cloth via a spacer with a thickness of 75 μm (masking tape with a thickness of 60 μm and baseless double-sided tape with a thickness of 15 μm). Was produced. The nylon mesh cloth was filled with a resin at openings other than 25 mm × 25 mm so that the powder could pass through only 25 mm × 25 mm.
_{Next, a particulate inorganic solid electrolyte material (Li 11} P ₃ ) is used in the space provided between the nylon mesh cloth and the PET plate (the space secured by the spacer) and the opening (void) of the nylon mesh cloth using a squeegee. S ₁₂ ) was filled.
Next, the nylon mesh cloth filled with the particulate inorganic solid electrolyte material is inverted and placed on the press die, and the PET plate is beaten with a wooden mallet and vibrated to be inorganic on the cavity surface of the press die. By sieving off the solid electrolyte material, the inorganic solid electrolyte material was deposited in the form of a film on the cavity surface of the press die. Here, the inorganic solid electrolyte material was deposited in a film shape with a uniform thickness in the cavity (25 mm × 25 mm) of the press die.
Then, a solid electrolyte sheet was obtained by pressing at 320 MPa using a hydraulic flat plate press. The battery characteristics of the obtained solid electrolyte sheet were evaluated. The results obtained are shown in Table 1.

<Examples 2 to 7>
Further, a particulate inorganic solid electrolyte material having the composition shown in Table 1 was obtained by a method according to the method for producing the Li ₂ SP ₂ S _{5 material having the composition of Li 11} P ₃ S _12. Each evaluation was performed on the obtained particulate inorganic solid electrolyte material. The results obtained are shown in Table 1.
Further, solid electrolyte sheets were prepared in the same manner as in Example 1 except that the types of the inorganic solid electrolyte materials were the inorganic solid electrolyte materials shown in Table 1, and the battery characteristics were evaluated respectively. The results obtained are shown in Table 1.

<Comparative example 1>
Particulate inorganic solid electrolyte materials and solid electrolyte sheets were prepared in the same manner as in Example 1 except that the operation of sieving with a nylon mesh (opening 100 μm) was not performed, and each evaluation was performed. The results obtained are shown in Table 2.

<Comparative Examples 2 to 7>
Particulate inorganic solid electrolyte materials were prepared in the same manner as in Examples 2 to 7 except that the operation of sieving with a nylon mesh (opening 100 μm) was not performed, and each evaluation was performed. The results obtained are shown in Table 2.
In addition, solid electrolyte sheets were prepared in the same manner as in Example 1 except that the type of the inorganic solid electrolyte material was the inorganic solid electrolyte material shown in Table 2, and each evaluation was performed. The results obtained are shown in Table 2.

The all-solid-state lithium-ion battery using the solid-state electrolyte sheet obtained in the examples was superior in battery characteristics to the all-solid-state lithium-ion battery using the solid-state electrolyte sheet obtained in the comparative example.
From the above, it was confirmed that the all-solid-state lithium-ion battery having excellent battery characteristics can be obtained according to the inorganic solid electrolyte material and the solid electrolyte sheet according to the present embodiment.
Hereinafter, an example of the reference form will be added.
1. 1.
An inorganic solid electrolyte material having lithium ion conductivity.
Inorganic solid electrolyte material elastic modulus is 0.5 × 10 9 ^Pa or more by nano-Day tension method of pressed compact obtained by the inorganic solid press 10 minutes molding an electrolyte material 500 MPa.
2.
1. 1. In the inorganic solid electrolyte material described in
Inorganic solid electrolyte material including sulfide-based inorganic solid electrolyte material.
3. 3.
2. In the inorganic solid electrolyte material described in
The sulfide-based inorganic solid electrolyte material is an inorganic solid electrolyte material containing Li, P, and S as constituent elements.
4.
3. 3. In the inorganic solid electrolyte material described in
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 of the S with respect to the P content. An inorganic solid electrolyte material having a molar ratio (S / P) of 1.0 or more and 10.0 or less.
5.
1. 1. To 4. In the inorganic solid electrolyte material described in any one of them,
The inorganic solid electrolyte material is in the form of particles and is in the form of particles.
Inorganic solid electrolyte in which the ratio (d ₉₀ / d ₅₀ ) of the particle size d _{90 to the average particle size d 50} of the inorganic solid electrolyte material in the weight-based particle size distribution measured by the laser diffraction / scattering type particle size distribution measurement method is 2.5 or less. material.
6.
5. In the inorganic solid electrolyte material described in
An inorganic solid electrolyte material having an average particle diameter d ₅₀ of the inorganic solid electrolyte material of 1 μm or more and 40 μm or less.
7.
1. 1. To 6. A solid electrolyte sheet containing the inorganic solid electrolyte material according to any one as a main component.
8.
A solid electrolyte sheet containing an inorganic solid electrolyte material having lithium ion conductivity as a main component.
The solid electrolyte sheet modulus by nano-Day tension method is 0.5 × 10 9 ^Pa or more.
9.
8. In the solid electrolyte sheet described in
A solid electrolyte sheet in which the inorganic solid electrolyte material contains a sulfide-based inorganic solid electrolyte material.
10.
9. In the solid electrolyte sheet described in
The sulfide-based inorganic solid electrolyte material is a solid electrolyte sheet containing Li, P, and S as constituent elements.
11.
10. In the solid electrolyte sheet described in
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 of the S with respect to the P content. A solid electrolyte sheet having a molar ratio (S / P) of 1.0 or more and 10.0 or less.
12.
7. To 11. In the solid electrolyte sheet according to any one,
A solid electrolyte sheet which is a pressure-molded body of the inorganic solid electrolyte material in the form of particles.
13.
7. To 12. In the solid electrolyte sheet according to any one,
A solid electrolyte sheet in which the content of the binder resin in the solid electrolyte sheet is less than 0.5% by mass when the total content of the solid electrolyte sheet is 100% by mass.
14.
7. To 13. In the solid electrolyte sheet according to any one,
A solid electrolyte sheet in which the content of the inorganic solid electrolyte material in the solid electrolyte sheet is 98% by mass or more when the total content of the solid electrolyte sheet is 100% by mass.
15.
7. To 14. In the solid electrolyte sheet according to any one,
A solid electrolyte sheet having an average thickness of 5 μm or more and 500 μm or less.
16.
7. To 15. In the solid electrolyte sheet according to any one,
A solid electrolyte sheet used for the solid electrolyte layer that constitutes an all-solid-state lithium-ion battery.
17.
An all-solid-state lithium-ion battery in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated in this order.
The solid electrolyte layer is 7. To 16. An all-solid-state lithium-ion battery composed of the solid electrolyte sheet according to any one of them.

200 All-solid-state lithium-ion battery 210 Positive electrode layer 220 Negative electrode layer 230 Solid electrolyte layer

Claims (8)

An inorganic solid electrolyte material having lithium ion conductivity.
The elastic modulus of the pressure-formed body obtained by press-molding the inorganic solid electrolyte material at 500 MPa for 10 minutes by the nanointention method is 0.5 × 10 ⁹ Pa or more and 1.0 × 10 ¹² Pa or less.
The inorganic solid electrolyte material contains a sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements.
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 of the S with respect to the P content. The molar ratio (S / P) of the content is 1.0 or more and 10.0 or less.
The inorganic solid electrolyte material is in the form of particles and is in the form of particles.
In weight particle size distribution by a laser diffraction scattering particle size distribution measuring method, the ratio _(d 90 _/ d ₅₀₎ of particle diameter _{d 90} for the mean particle size _{d 50} of the inorganic solid electrolyte material Ri der 2.2 or less,
An inorganic solid electrolyte material having an average particle diameter d ₅₀ of 2 μm or more and 40 μm or less. A solid electrolyte sheet containing the inorganic solid electrolyte material according to claim 1. A solid electrolyte sheet containing an inorganic solid electrolyte material having lithium ion conductivity.
The elastic modulus by the nanointention method is 0.5 × 10 ⁹ Pa or more and 1.0 × 10 ¹² Pa or less.
The inorganic solid electrolyte material contains a sulfide-based inorganic solid electrolyte material containing Li, P, and S as constituent elements.
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 of the S with respect to the P content. The molar ratio (S / P) of the content is 1.0 or more and 10.0 or less.
It is a pressure-molded article of the inorganic solid electrolyte material in the form of particles.
In weight particle size distribution by a laser diffraction scattering particle size distribution measuring method, the ratio _(d 90 _/ d ₅₀₎ of particle diameter _{d 90} for the mean particle size _{d 50} of the inorganic solid electrolyte material Ri der 2.2 or less,
A solid electrolyte sheet having an average particle diameter d ₅₀ of 2 μm or more and 40 μm or less. In the solid electrolyte sheet according to claim 3,
A solid electrolyte sheet in which the content of the binder resin in the solid electrolyte sheet is less than 0.5% by mass when the total content of the solid electrolyte sheet is 100% by mass. In the solid electrolyte sheet according to claim 3 or 4.
A solid electrolyte sheet in which the content of the inorganic solid electrolyte material in the solid electrolyte sheet is 98% by mass or more when the total content of the solid electrolyte sheet is 100% by mass. In the solid electrolyte sheet according to any one of claims 3 to 5,
A solid electrolyte sheet having an average thickness of 5 μm or more and 500 μm or less. In the solid electrolyte sheet according to any one of claims 3 to 6.
A solid electrolyte sheet used for the solid electrolyte layer that constitutes an all-solid-state lithium-ion battery. An all-solid-state lithium-ion battery in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated in this order.
An all-solid-state lithium-ion battery in which the solid electrolyte layer is formed of the solid electrolyte sheet according to any one of claims 3 to 7.

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