A sulfide solid electrolyte is provided having: diffraction peak A observed within a range of 2θ=20.0° to 24.0°; and diffraction peak B observed within a range of 2θ=24.4° to 26.4°, diffraction peak A and diffraction peak B being observed by performing X-ray diffraction measurement using CuKα1 radiation, and the ratio of I.sub.A to I.sub.B, I.sub.A/I.sub.B, being 2.0 or less, wherein I.sub.A is an intensity of diffraction peak A and I.sub.B is an intensity of diffraction peak B. Preferably, the sulfide solid electrolyte contains elemental lithium, elemental phosphorus, elemental sulfur, and an elemental halogen. It is also preferable that the sulfide solid electrolyte has an argyrodite-type crystal structure. It is also preferable that the sulfide solid electrolyte contains a lithium halide hydrate.

Provided is a diphosphorus pentasulfide composition for a sulfide-based inorganic solid electrolyte material, in which a molar ratio (S/P) of a content of sulfur (S) to a content of phosphorus (P) is 2.40 or higher and 2.49 or lower. In the diphosphorus pentasulfide composition for a sulfide-based inorganic solid electrolyte material, in a DSC curve of the diphosphorus pentasulfide composition obtained by measurement using a differential scanning calorimeter under conditions of a start temperature of 25° C., a measured temperature range of 30° C. to 350° C., a temperature increase rate of 5° C./min, and an argon atmosphere with a flow rate of 100 ml per minute, an endothermic peak is shown in a temperature range of 280° C. or higher and 300° C. or lower, and a half-width of the endothermic peak is 4.1° C. or higher.

Provided is a method of manufacturing a sulfide-based inorganic solid electrolyte material including Li, P, and S as constituent elements, the method including: a preparation step of preparing a raw material inorganic composition (A) including at least lithium sulfide, phosphorus sulfide, and a crystal nucleating agent; and a vitrification step of mechanically processing the raw material inorganic composition (A) to vitrify the raw material inorganic composition (A).

Provided is a lithium nitride composition for a sulfide-based inorganic solid electrolyte material including α-lithium nitride, wherein in a spectrum obtained by X-ray diffraction in which a CuKα ray is used as a radiation source, when a diffraction intensity of a diffraction peak present at a position of a diffraction angle 2θ=23.0±0.3° is represented by I.sub.α and a diffraction intensity of a diffraction peak present at a position of a diffraction angle 2θ=32.0±0.3° is represented by I.sub.β, a value of I.sub.β/I.sub.α is 4.50 or lower.

A sulfide solid electrolyte that contains lithium, phosphorus, sulfur, chlorine and bromine, wherein in powder X-ray diffraction analysis using CuKα rays, it has a diffraction peak A at 2θ=25.2±0.5 deg and a diffraction peek B at 2θ=29.7±0.5 deg, the diffraction peak A and the diffraction peak B satisfy the following formula (A), and a molar ratio of the chlorine to the phosphorus “c (Cl/P)” and a molar ratio of the bromine to the phosphorus “d (Br/P)” satisfies the following formula (1):
1.2<c+d<1.9  (1)
0.845<S.sub.A/S.sub.B<1.200  (A) where S.sub.A is an area of the diffraction peak A and S.sub.B is an area of the diffraction peak B.

A sulfide solid electrolyte that contains lithium, phosphorus, sulfur, chlorine and bromine, wherein in powder X-ray diffraction analysis using CuKα rays, it has a diffraction peak A at 2θ=25.2±0.5 deg and a diffraction peek B at 2θ=29.7±0.5 deg, the diffraction peak A and the diffraction peak B satisfy the following formula (A), and a molar ratio of the chlorine to the phosphorus “c (Cl/P)” and a molar ratio of the bromine to the phosphorus “d (Br/P)” satisfies the following formula (1):
1.2<c+d<1.9  (1)
0.845<S.sub.A/S.sub.B<1.200  (A) where S.sub.A is an area of the diffraction peak A and S.sub.B is an area of the diffraction peak B.

Disclosed is a method for producing a sulfide solid electrolyte including a step of processing a slurry by at least one treatment selected from drying and heating, wherein a solid electrolyte raw material containing a lithium element, a sulfur element, a phosphorus element and a halogen element, and a complexing agent are mixed in a reactor to give a complex slurry containing a complex formed of the solid electrolyte raw material and the complexing agent, and the complex slurry is transferred into an intermediate tank equipped with a cooling device and cooled therein.

Disclosed is a method for producing a sulfide solid electrolyte including a step of processing a slurry by at least one treatment selected from drying and heating, wherein a solid electrolyte raw material containing a lithium element, a sulfur element, a phosphorus element and a halogen element, and a complexing agent are mixed in a reactor to give a complex slurry containing a complex formed of the solid electrolyte raw material and the complexing agent, and the complex slurry is transferred into an intermediate tank equipped with a cooling device and cooled therein.

Methods of manufacturing conductive molybdenum disulfide (MoS.sub.2) are described herein. The methods include mixing a molybdenum disulfide powder in a liquid to form a molybdenum disulfide suspension, sonicating the molybdenum disulfide suspension for a first period of time at a first temperature, and retrieving the conductive molybdenum disulfide from the sonicated molybdenum disulfide suspension. Methods of manufacturing conductive forms of other transition metal dichalcogenides are also described. Materials produced by the methods described herein are also described.

Methods of manufacturing conductive molybdenum disulfide (MoS.sub.2) are described herein. The methods include mixing a molybdenum disulfide powder in a liquid to form a molybdenum disulfide suspension, sonicating the molybdenum disulfide suspension for a first period of time at a first temperature, and retrieving the conductive molybdenum disulfide from the sonicated molybdenum disulfide suspension. Methods of manufacturing conductive forms of other transition metal dichalcogenides are also described. Materials produced by the methods described herein are also described.