A method for preparing a lithium ion conductive sulfide, which is capable of independently controlling the elemental ratio of lithium (Li), phosphorus (P), sulfur (S), etc, is provided. The method for preparing a lithium ion conductive sulfide can provide a lithium ion conductive sulfide having a crystal structure and an anion cluster distribution distinguished from those of existing ones.

Disclosed is a solid electrolyte for an all-solid battery and a method of preparing the same. Particularly, the solid electrolyte may have an argyrodite-type crystal structure.

Disclosed is a solid electrolyte for an all-solid battery and a method of preparing the same. Particularly, the solid electrolyte may have an argyrodite-type crystal structure.

A method for producing a solid electrolyte including step of bringing the following into contact with each other in a solvent having a solubility parameter of 9.0 or more: an alkali metal sulfide; one or two or more sulfur compounds selected from phosphorus sulfide, germanium sulfide, silicon sulfide and boron sulfide; and a halogen compound.

A method for producing a solid electrolyte including step of bringing the following into contact with each other in a solvent having a solubility parameter of 9.0 or more: an alkali metal sulfide; one or two or more sulfur compounds selected from phosphorus sulfide, germanium sulfide, silicon sulfide and boron sulfide; and a halogen compound.

Provided is a positive electrode material including a positive electrode active material, a first solid electrolyte material, and a coating material. The coating material is located on the surface of the positive electrode active material. The first solid electrolyte material includes lithium, at least one kind selected from the group consisting of metalloid elements and metal elements other than lithium, and at least one kind selected from the group consisting of chlorine, bromine, and iodine. The first solid electrolyte material does not include sulfur.

An object of the present invention is to provide a novel sulfur-based positive electrode active material for a lithium-ion secondary battery which is excellent in cyclability and can largely improve a charging and discharging capacity, a positive electrode comprising the positive electrode active material and a lithium-ion secondary battery made using the positive electrode. The sulfur-based positive electrode active material is obtainable by subjecting a starting material comprising a polymer, sulfur and an organometallic compound dispersed in a form of fine particles to heat-treatment under a non-oxidizing atmosphere, wherein the particles of metallic sulfide resulting from sulfurization of the organometallic compound are dispersed in the heat-treated material, and particle size of the metallic sulfide particles is not less than 10 nm and less than 100 nm.

An object of the present invention is to provide a novel sulfur-based positive electrode active material for a lithium-ion secondary battery which is excellent in cyclability and can largely improve a charging and discharging capacity, a positive electrode comprising the positive electrode active material and a lithium-ion secondary battery made using the positive electrode. The sulfur-based positive electrode active material is obtainable by subjecting a starting material comprising a polymer, sulfur and an organometallic compound dispersed in a form of fine particles to heat-treatment under a non-oxidizing atmosphere, wherein the particles of metallic sulfide resulting from sulfurization of the organometallic compound are dispersed in the heat-treated material, and particle size of the metallic sulfide particles is not less than 10 nm and less than 100 nm.

An object of the invention is to provide a sulfide solid electrolyte material with high heat stability. In the invention, the object is achieved by providing a sulfide solid electrolyte material comprising an ion conductor having (i) a Li element and (ii) an anion structure containing at least a P element, wherein a main component of the anion structure is PS.sub.4.sup.3−, and the ion conductor has the PS.sub.4.sup.3− and PS.sub.3O.sup.3− as the anion structure, but has neither PS.sub.2O.sub.2.sup.3− nor PSO.sub.3.sup.3−.

A main object of the present disclosure is to provide a sulfide solid electrolyte material with favorable Li ion conductivity. To achieve the above object, the present disclosure provides a sulfide solid electrolyte material comprising a composition of Li.sub.(4+x)Al.sub.xSi.sub.(1−x)S.sub.4 (0<x<1), and having a peak at a position of 2θ=25.19°±1.00°, 29.62°±1.00°, 30.97°±1.00° in X-ray diffraction measurement using a CuKα ray.