Method for producing sulfide-based solid electrolyte material

Abstract

This method for producing a sulfide-based solid electrolyte material comprises: a starting material preparation step (S01) for preparing an electrolyte starting material that contains an element constituting the sulfide-based solid electrolyte material; and a synthesis step (S02) for synthesizing the sulfide-based solid electrolyte material by heating the electrolyte starting material. In the starting material preparation step (S01), the ratio of P in the electrolyte starting material is set within the range of 1.01 to 1.07 times the stoichiometric amount ratio of the target composition.

Description

Method for producing sulfide-based solid electrolyte material

[0001] This invention relates to a method for producing a sulfide-based solid electrolyte material suitable for use in, for example, all-solid-state batteries, etc. This application claims priority based on Japanese Patent Application No. 2024-089872 filed in Japan on June 3, 2024, International Application No. PCT / JP2025 / 000828 filed in Japan on January 14, 2025, and Japanese Patent Application No. 2025-024940 filed in Japan on February 19, 2025, the contents of which are incorporated herein by reference.

[0002] In recent years, sulfide-based solid electrolyte materials have attracted attention as electrolytes for lithium-ion secondary batteries because they have high ionic conductivity and are safer than liquid electrolytes. A widely used method for producing sulfide-based solid electrolyte materials involves first mechanically milling a mixture of raw materials to vitrify or amorphousize them, followed by heat treatment and synthesis of the sulfide-based solid electrolyte material through a solid-state reaction.

[0003] For example, Patent Document 1 describes a method for producing sulfide glass and glass ceramics, which are types of sulfide-based solid electrolyte materials, in which a mixture of metallic lithium, elemental sulfur, and elemental phosphorus is vitrified by mechanical milling and then heat-treated. Patent Documents 2 and 3 also describe a method for producing a sulfide-based solid electrolyte material with an LGPS crystal structure in which a mixture of various sulfides is amorphized by mechanical milling, then heat-treated, and crystallized by a solid-phase reaction. That is, a method in which a mixture of electrolyte raw materials is subjected to mechanical milling to diffuse and mix the contained elements and homogenize the chemical composition of the entire mixture before heat treatment has become a common method for producing sulfide-based solid electrolyte materials with sufficient ionic conductivity.

[0004] Furthermore, Patent Document 4 describes a method for producing a sulfide-based solid electrolyte material, in which raw materials containing elemental sulfur are mixed in such a ratio that the volume ratio of elemental sulfur to the entire aggregate of the starting materials when heated to 120°C is 20% or more, and the mixture is heat-treated.

[0005] Japanese Patent Publication No. 2003-208919 Japanese Patent No. 5527673 Japanese Patent No. 5888609 Japanese Patent Publication No. 2023-048303

[0006] However, in general methods for producing sulfide-based solid electrolyte materials, mechanical milling is performed as described in Patent Documents 1 to 3. However, because mechanical milling requires a large amount of energy and a long time, it is not possible to efficiently produce sulfide-based solid electrolyte materials, and it is difficult to scale up the equipment. Furthermore, because the sulfide-based solid electrolyte material is synthesized by a solid-state reaction, the chemical composition of the synthesized sulfide-based solid electrolyte becomes non-uniform, and there is a risk that the ionic conductivity of the sulfide-based solid electrolyte will not be sufficiently improved.

[0007] In Patent Document 4, a sulfide-based solid electrolyte material is produced by heat-treating a starting material mixed with elemental sulfur without performing mechanical milling, which makes it possible to efficiently produce a sulfide-based solid electrolyte material without requiring large amounts of energy and a long time as with mechanical milling. However, when the starting material is heat-treated, the P contained in the starting material volatilizes, resulting in a shortage of P in the composition of the product and the resulting lack of PS. ４ ３－ , P ２ S ７ ４－ , P ２ S ６ ４－ This makes it difficult to form a framework structure such as the above. As a result, there are not enough substitution sites for halogen elements, and sulfur-halogen-based raw materials remain, which could reduce the ionic conductivity of the sulfide-based solid electrolyte material.

[0008] In all-solid-state batteries and the like that use sulfide-based solid electrolyte materials, low ionic conductivity of the sulfide-based solid electrolyte material results in increased resistance. The sulfide-based solid electrolyte materials produced by the production methods described in Patent Documents 1 to 4 have insufficient ionic conductivity and could not be used as sulfide-based solid electrolyte materials for constructing high-power batteries.

[0009] The present invention has been made in view of the above-mentioned circumstances, and aims to provide a method for producing a sulfide-based solid electrolyte material that is excellent in ionic conductivity and that is particularly suitable for high-power solid-state batteries, and that can efficiently produce such a sulfide-based solid electrolyte material.

[0010] In order to solve the above problems, a method for producing a sulfide-based solid electrolyte material according to Aspect 1 of the present invention includes a raw material preparation step of preparing an electrolyte raw material containing elements that constitute the sulfide-based solid electrolyte material, and a synthesis step of heating the electrolyte raw material to synthesize the sulfide-based solid electrolyte material, wherein in the raw material preparation step, a ratio of P in the electrolyte raw material is set within a range of 1.01 to 1.07 times the stoichiometric ratio of a target composition.

[0011] According to the method for producing a sulfide-based solid electrolyte material of the first aspect of the present invention, in the raw material preparation step, the ratio of P in the electrolyte raw material is set to a range of 1.01 times or more and 1.07 times or less with respect to the stoichiometric ratio of the target composition. Therefore, even if a part of P volatilizes when the electrolyte raw material is heated in the synthesis step, PS ４ ３－ , P ２ S ７ ４－ , P ２ S ６ ４－ The above-mentioned framework structure is sufficiently formed, and the remaining sulfur-halogen-based raw materials can be suppressed, thereby obtaining a sulfide-based solid electrolyte material with high ionic conductivity. Furthermore, processes requiring large amounts of energy and long times, such as mechanical milling, are no longer necessary, and the sulfide-based solid electrolyte material can be produced efficiently.

[0012] A method for producing a sulfide-based solid electrolyte material according to Aspect 2 of the present invention is the method for producing a sulfide-based solid electrolyte material according to Aspect 1 of the present invention, wherein the sulfide-based solid electrolyte material is a sulfide-based solid electrolyte material having a space group P4 ２ / nmc belonging LGPS (Li １０ GeP ２ S １２ According to the method for producing a sulfide-based solid electrolyte material of the second aspect of the present invention, LGPS (Li １０ GeP２ S １２ ) type crystal structure and can efficiently produce a sulfide-based solid electrolyte material with excellent ionic conductivity.

[0013] A method for producing a sulfide-based solid electrolyte material according to Aspect 3 of the present invention is characterized in that, in the method for producing a sulfide-based solid electrolyte material according to Aspect 1 of the present invention, the sulfide-based solid electrolyte material has an Argyrodite-type crystal structure. According to the method for producing a sulfide-based solid electrolyte material according to Aspect 3 of the present invention, it is possible to efficiently produce a sulfide-based solid electrolyte material having an Argyrodite-type crystal structure and excellent ionic conductivity.

[0014] According to an aspect of the present invention, it is possible to provide a method for producing a sulfide-based solid electrolyte material that is excellent in ionic conductivity and is particularly suitable for high-power solid-state batteries, and that can efficiently produce such a sulfide-based solid electrolyte material.

[0015] FIG. 1 is a flow chart showing an example of a method for producing a sulfide-based solid electrolyte material according to an embodiment of the present invention.

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the following embodiments are specifically described to provide a better understanding of the gist (technical requirements) of the invention, and do not limit the present invention unless otherwise specified.

[0017] The method for producing a sulfide-based solid electrolyte material according to this embodiment is for producing a sulfide-based solid electrolyte material to be used as a solid electrolyte in an all-solid-state battery, for example. Sulfide-based solid electrolyte materials have relatively high ionic conductivity, are non-flammable, and are highly safe, and therefore are applied to electric vehicles and the like. Here, in order to construct a high-power solid-state battery, a sulfide-based solid electrolyte material with even better ionic conductivity is required.

[0018] In addition, the sulfide-based solid electrolyte material produced in this embodiment may be, for example, a sulfide-based solid electrolyte material having a space group P4 ２ / nmc belonging LGPS (Li １０ GeP ２ S １２) type crystal structure of LGPS material or LiSiPSCl material (Li １０．０２ Si １．４７ P １．５６ S １１．７ Cl ０．３ ) and Argyrodite materials (Li ５．５ P.S. ４．５ Cl １．５ ), or an LMS material having Li, S, and at least one element of groups 13, 14, and 15 (Li ４ MS ４ ) etc.

[0019] Here, the method for producing a sulfide-based solid electrolyte material according to this embodiment will be described with reference to the flow diagram of Fig. 1. As shown in Fig. 1, the method for producing a sulfide-based solid electrolyte material according to this embodiment includes a raw material preparation step S01 for preparing an electrolyte raw material containing elements that constitute the sulfide-based solid electrolyte material, and a synthesis step S02 for heating the obtained electrolyte raw material to produce (synthesize) a sulfide-based solid electrolyte.

[0020] (Raw material preparation step S01) First, an electrolyte raw material containing elements constituting the sulfide-based solid electrolyte material is prepared. The electrolyte raw material is preferably at least one selected from simple substances of the elements constituting the sulfide-based solid electrolyte material, compounds of the elements constituting the sulfide-based solid electrolyte material, and sulfides of the elements constituting the sulfide-based solid electrolyte material. Furthermore, in this embodiment, the electrolyte raw material preferably does not contain elements other than the elements constituting the sulfide-based solid electrolyte material, except for unavoidable impurities.

[0021] In the method for producing a sulfide-based solid electrolyte material according to this embodiment, the ratio (molar ratio) of P contained in the electrolyte raw material is set to be 1.01 to 1.07 times the stoichiometric ratio of the target composition in the raw material preparation step S01. That is, the electrolyte raw material is blended so as to contain more P than the stoichiometric ratio of the target composition.

[0022] Here, if the ratio of P contained in the electrolyte raw material is less than 1.01 times the stoichiometric ratio of the target composition, P will volatilize when heated in the synthesis step S02 described below, resulting in a shortage of P, and PS ４ ３－ , P ２ S ７ ４－ , P ２ S ６ ４－ In this case, it may be impossible to sufficiently form a skeletal structure such as the above, which may result in a decrease in the ionic conductivity of the produced sulfide-based solid electrolyte material. On the other hand, if the ratio of P contained in the electrolyte raw material exceeds 1.07 times the stoichiometric ratio of the target composition, unnecessary skeletons may be formed by the excess P, which may result in a decrease in the ionic conductivity of the produced sulfide-based solid electrolyte material. For these reasons, in this embodiment, the ratio of P contained in the electrolyte raw material is set to be within a range of 1.01 to 1.07 times the stoichiometric ratio of the target composition.

[0023] The ratio of P contained in the electrolyte raw material is preferably 1.02 times or more the stoichiometric ratio of the target composition, and is preferably 1.06 times or less, and more preferably 1.05 times or less, the stoichiometric ratio of the target composition.

[0024] Furthermore, in the raw material preparation step S01, there are no particular limitations on the method as long as it can uniformly mix the raw materials, and examples of various existing methods include a general mixer, blender, ball mill, bead mill, vibration mill, V-type mixer, etc. Furthermore, instead of a general mixing process, mixing may be performed using a planetary ball mill, vibration mill, ball mill, etc.

[0025] In this embodiment, the electrolyte raw material is preferably mixed so that a diffraction peak due to the crystalline substance contained in the electrolyte raw material is detected when the X-ray diffraction pattern of the electrolyte raw material is measured. That is, it is preferable not to apply a method that applies a large amount of energy, such as mechanical milling, during mixing so that the crystalline substance contained in the electrolyte raw material is not altered.

[0026] The mixing process in the raw material preparation step S01 is preferably carried out in an inert atmosphere such as nitrogen, argon, or other rare gases. Additionally, the atmospheric gas used preferably does not contain oxygen, and the oxygen concentration in the atmospheric gas is preferably 50 ppm or less, more preferably 30 ppm or less, and even more preferably 10 ppm or less. The oxygen concentration is specifically expressed in vol ppm. The dew point is preferably -50°C or less, more preferably -60°C or less, and even more preferably -70°C or less.

[0027] (Synthesis step S02) In this synthesis step S02, the electrolyte raw material is heated to synthesize a sulfide-based solid electrolyte material. The heating temperature in the synthesis step S02 is preferably 400°C or higher, more preferably 450°C or higher, and even more preferably 500°C or higher. On the other hand, the heating temperature in the synthesis step S02 is preferably 1000°C or lower, and more preferably 650°C or lower.

[0028] The holding time at the heating temperature is preferably 0.5 hours or more, more preferably 1.0 hour or more, while the holding time at the heating temperature is preferably 72 hours or less, more preferably 24 hours or less, and even more preferably 12 hours or less.

[0029] The heat treatment in synthesis step S02 is preferably carried out in an inert atmosphere such as nitrogen, argon, or other rare gases. In addition, the atmospheric gas used preferably does not contain oxygen, and the oxygen concentration in the atmospheric gas is preferably 50 ppm or less, more preferably 30 ppm or less, and even more preferably 10 ppm or less. The dew point is preferably −50° C. or less, more preferably −60° C. or less, and even more preferably −70° C. or less.

[0030] The average rate of temperature rise from room temperature (25°C) to the heating temperature is preferably 0.1°C / min or more, more preferably 1°C / min or more, and even more preferably 5°C / min or more. On the other hand, the average rate of temperature rise from room temperature (25°C) to the heating temperature is preferably 20°C / min or less, more preferably 15°C / min or less, and even more preferably 10°C / min or less.

[0031] The average cooling rate from the heating temperature to room temperature (25°C) is preferably 0.1°C / min or more, more preferably 0.5°C / min or more, and even more preferably 2°C / min. On the other hand, the average cooling rate from the heating temperature to room temperature (25°C) is preferably 50°C / min or less, more preferably 40°C / min or less, and even more preferably 30°C / min or less.

[0032] Through the above steps, a sulfide-based solid electrolyte material is produced.

[0033] Here, as the raw material for the electrolyte, Li ２ When a mixture of S, Ge, P (red phosphorus), and elemental sulfur S is used, in the synthesis step S02, the LGPS material (Li １０ GeP ２ S １２ ) is produced. ２ S+Ge+2P+7S→Li １０ GeP ２ S １２ In this case, the target composition is Li １０ GeP ２ S １２ and the stoichiometric ratio of P in the target composition is 2. In the raw material preparation step S01, the ratio of P in the electrolyte raw material is set to be in the range of 1.01 to 1.07 times the stoichiometric ratio of P in the target composition, which is 2.

[0034] As a raw material for electrolytes, Li ２ When a mixture of S, Si, P, S, and LiCl is used, in the synthesis step S02, LiSiPSCl (Li １０．０２ Si １．４７ P１．５６ S １１．７ Cl ０．３ In this case, the target composition is Li １０．０２ Si １．４７ P １．５６ S １１．７ Cl ０．３ In the raw material preparation step S01, the ratio of P in the electrolyte raw material is set to be in the range of 1.01 to 1.07 times the stoichiometric ratio of P in the target composition, 1.56.

[0035] As a raw material for electrolytes, Li ２ When a mixture of S, LiCl, P, and elemental sulfur S is used, in the synthesis step S02, an Argyrodite material having an Argyrodite-type crystal structure (Li ５．５ P.S. ４．５ Cl １．５ In this case, the target composition is Li ５．５ P.S. ４．５ Cl １．５ and the stoichiometric ratio of P in the target composition is 1. In the raw material preparation step S01, the ratio of P in the electrolyte raw material is set to be in the range of 1.01 to 1.07 times the stoichiometric ratio of P of 1 in the target composition.

[0036] As a raw material for electrolytes, Li ２ When a mixture of S, P (red phosphorus), and elemental sulfur S is used, the LMS material (Li ４ MS ４ In this case, the target composition is Li ４ MS ４ (M=P), and the stoichiometric ratio of P in the target composition is 1. In the raw material preparation step S01, the ratio of P in the electrolyte raw material is set to be in the range of 1.01 to 1.07 times the stoichiometric ratio of P of the target composition, which is 1.

[0037] According to the method for producing a sulfide solid electrolyte material of this embodiment configured as described above, in the raw material preparation step S01, the ratio of P in the raw material for the electrolyte is set to a range of 1.01 times or more and 1.07 times or less with respect to the stoichiometric ratio of the target composition. Therefore, even if a part of P volatilizes when the raw material for the electrolyte is heated in the synthesis step S02, the PS４ ３－ , P ２ S ７ ４－ , P ２ S ６ ４－ This allows for the formation of a sufficient framework structure such as the above. This ensures sufficient substitution sites for halogen elements, suppresses the residue of sulfur-halogen-based raw materials, and enables the production of a sulfide-based solid electrolyte material with high ionic conductivity. Furthermore, since processes requiring large amounts of energy and long periods of time, such as mechanical milling, are no longer necessary, the sulfide-based solid electrolyte material can be produced efficiently.

[0038] In the method for producing a sulfide solid electrolyte material according to the present embodiment, Li is used as a raw material for the electrolyte. ２ When a mixture of S, Ge, P (red phosphorus) and elemental sulfur S is used, as described above, LGPS (Li １０ GeP ２ S １２ ) type crystal structure and has excellent ionic conductivity. １０ GeP ２ S １２ ) can be produced efficiently.

[0039] In the method for producing a sulfide solid electrolyte material according to the present embodiment, Li is used as a raw material for the electrolyte. ２ When a mixture of S, Si, P, S, and LiCl is used, as described above, LGPS (Li １０ GeP ２ S １２ )-type crystal structure and has excellent ionic conductivity. １０．０２ Si １．４７ P １．５６ S １１．７ Cl ０．３ ) can be efficiently produced.

[0040] In the method for producing a sulfide solid electrolyte material according to the present embodiment, Li is used as a raw material for the electrolyte. ２ When a mixture of S, LiCl, P, and elemental sulfur S is used, a sulfide-based solid electrolyte material (LiCl) with an Argyrodite-type crystal structure and excellent ionic conductivity is obtained.５．５ P.S. ４．５ Cl １．５ ) can be produced efficiently.

[0041] Although one embodiment of the present invention has been described above, the present invention is not limited thereto and can be modified as appropriate within the scope of the technical requirements of the invention. For example, if there is a risk that part of the S (sulfur) in the electrolyte raw material will evaporate due to heating in the synthesis step S02, the ratio (molar ratio) of S in the electrolyte raw material may be made higher than the stoichiometric ratio of the target composition.

[0042] A confirmation experiment conducted to confirm the effectiveness of the present invention will be described.

[0043] (Invention Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-2) As a raw material preparation step, Li ２ S, Si, P, S, and LiCl were prepared, and the LiCl was ２ S, Si, and LiCl were weighed to obtain the desired composition, and elemental sulfur was weighed in an amount 1.5 times the weight required for the element ratio in the raw material mixture to be equal to the target composition. Then, P was added, and the ratio of P in the electrolyte raw material was adjusted to the target composition (Li １０．０２ Si １．４７ P １．５６ S １１．７ Cl ０．３ The ratios were adjusted to the multiplication factors shown in Table 1 relative to the stoichiometric ratio of

[0044] The electrolyte raw materials prepared as described above were mixed in an agate mortar for 5 minutes until the color became uniform. In the synthesis process, the mixed electrolyte raw materials were placed in a furnace, and the furnace was heated to 550°C at 5°C / min in an argon atmosphere and held at 550°C for 6 hours. Thereafter, the mixture was cooled to room temperature at 2°C / min to obtain a sulfide-based solid electrolyte material (LGPS-type LiSiPSCl(Li １０．０２ Si １．４７ P １．５６ S １１．７ Cl ０．３ )) was obtained.

[0045] (Invention Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-2) As a raw material preparation step, Li２ S, P, S, and LiCl were prepared, and the LiCl was heated in an argon atmosphere in a glove box with a dew point of -70°C or less and an oxygen concentration of 10 ppm or less. ２ S and LiCl were weighed to obtain the desired composition, and elemental sulfur was weighed in an amount 1.5 times the weight required for the element ratio in the raw material mixture to be equal to the target composition. Then, P was added, and the ratio of P in the electrolyte raw material was adjusted to the target composition (Li ５．５ P.S. ４．５ Cl １．５ The ratios were adjusted to the multiplication factors shown in Table 1 relative to the stoichiometric ratio of

[0046] The electrolyte raw materials prepared as described above were mixed in an agate mortar for 5 minutes until the color became uniform. In the synthesis process, the mixed electrolyte raw materials were placed in a furnace, and the furnace was heated to 500°C at 0.5°C / min in an argon atmosphere and held at 500°C for 5 hours. Thereafter, the mixture was cooled to room temperature at 2°C / min to obtain a sulfide-based solid electrolyte material (Argyrodite material (Li ５．５ P.S. ４．５ Cl １．５ )) was obtained.

[0047] The ionic conductivity of the obtained sulfide-based solid electrolyte material was measured as follows. The measurement results are shown in Table 1. The sulfide-based solid electrolyte material was removed from the glove box in an argon atmosphere and then crushed in an agate mortar. 0.3 g was weighed out and filled into a stainless steel ionic conductivity measurement cell (cylindrical with an inner diameter of 17 mm). Then, using a measuring device "Potentio / Galvanostat SP-300" manufactured by Biologic, Inc., the ionic conductivity (mS / cm) was measured by an AC impedance method under the conditions of a measurement temperature of 25°C, a measurement frequency of 1 Hz to 1 MHz, and an applied pressure of 360 MPa to the measurement cell. The evaluation results are shown in Table 1.

[0048]

[0049] Inventive Examples 1-1 to 1-3 and Comparative Examples 1-1 and 1-2 are LGPS-type sulfide-based solid electrolyte materials.

[0050] In Comparative Example 1-1, the ratio of P in the electrolyte raw material was 1.00 times the stoichiometric ratio of the target composition, and the ionic conductivity was low at 3.1 mS / cm. This is presumably because P was insufficient and a skeletal structure could not be formed sufficiently. In Comparative Example 1-2, the ratio of P in the electrolyte raw material was 1.09 times the stoichiometric ratio of the target composition, and the ionic conductivity was low at 1.9 mS / cm. This is presumably because P was present in excess and an unnecessary skeletal structure was formed.

[0051] In contrast, in Examples 1-1 to 1-3 of the present invention, in which the ratio of P in the electrolyte raw material was within the range of 1.01 to 1.07 times the stoichiometric ratio of the target composition, the ionic conductivity was high, at 3.8 mS / cm or more. This is presumably because there was no shortage of P in the synthesis process, and the skeletal structure was able to be appropriately formed.

[0052] Inventive Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-2 are sulfide-based solid electrolyte materials having an argyrodite-type crystal structure.

[0053] In Comparative Example 2-1, the ratio of P in the electrolyte raw material was 1.00 times the stoichiometric ratio of the target composition, resulting in a low ionic conductivity of 1.4 mS / cm. This is presumably because P was insufficient and a skeletal structure could not be formed sufficiently. In Comparative Example 2-2, the ratio of P in the electrolyte raw material was 1.09 times the stoichiometric ratio of the target composition, resulting in a low ionic conductivity of 0.76 mS / cm. This is presumably because an unnecessary skeletal structure was formed due to the presence of an excess of P.

[0054] In contrast, in Examples 2-1 to 2-3 of the present invention, in which the ratio of P in the electrolyte raw material was within the range of 1.01 to 1.07 times the stoichiometric ratio of the target composition, the ionic conductivity was high, at 2.0 mS / cm or more. This is presumably because there was no shortage of P in the synthesis process, and the skeletal structure was able to be appropriately formed.

[0055] As a result of the above confirmatory experiments, it was confirmed that the present invention can provide a method for producing a sulfide-based solid electrolyte material that is excellent in ionic conductivity and is particularly suitable for high-power solid-state batteries, and that can efficiently produce such a sulfide-based solid electrolyte material.

[0056] The method for producing a sulfide-based solid electrolyte material of the present embodiment is suitably applied to the production process of a sulfide-based solid electrolyte material used in an all-solid-state battery or the like.

[0057] S01 raw material preparation process, S02 synthesis process.

Claims

1. A method for producing a sulfide-based solid electrolyte material, comprising: a raw material preparation step of preparing an electrolyte raw material containing elements that constitute the sulfide-based solid electrolyte material; and a synthesis step of heating the electrolyte raw material to synthesize the sulfide-based solid electrolyte material, wherein in the raw material preparation step, a ratio of P in the electrolyte raw material is set within a range of 1.01 to 1.07 times the stoichiometric ratio of a target composition.

2. The sulfide-based solid electrolyte material has a space group P4 ２ / nmc belonging LGPS (Li １０ GeP ２ S １２ 2. The method for producing a sulfide-based solid electrolyte material according to claim 1, characterized in that the sulfide-based solid electrolyte material has a crystalline structure of the sulphide-based solid electrolyte material.

3. The method for producing a sulfide-based solid electrolyte material according to claim 1, characterized in that the sulfide-based solid electrolyte material has an argyrodite-type crystal structure.

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