There is provided a solid electrolyte production method which can provide a solid electrolyte having a high ion conductivity at low cost with high productivity using a liquid-phase method. The method comprises drying a slurry by fluidized drying using media particles as a medium. The slurry includes a solid electrolyte comprising at least an alkali metal, sulfur atoms and phosphorus atoms as constituent atoms, or a precursor of the solid electrolyte, and a polar solvent.

There are provided an inorganic solid electrolyte-containing composition that has excellent dispersion characteristics and excellent application suitability and enables excellent cycle characteristics, a sheet for an all-solid state secondary battery, and an all-solid state secondary battery, and manufacturing methods for a sheet for an all-solid state secondary battery and an all-solid state secondary battery, in which the above inorganic solid electrolyte-containing composition is used. The inorganic solid electrolyte-containing composition for an all-solid state secondary battery contains an inorganic solid electrolyte, a polymer binder, and a dispersion medium, in which an adsorption rate of the polymer binder with respect to the inorganic solid electrolyte is 50% or less, and the inorganic solid electrolyte and the polymer binder satisfies a specific relationship in terms of surface energy.

The present application discloses a sulfide solid electrolyte and a method for the preparation thereof, an all solid state lithium secondary battery, and an apparatus containing the all solid state lithium secondary battery. The sulfide solid electrolyte is obtained by compounding at least Li.sub.2S, P.sub.2S.sub.5 and a dopant M.sub.xS.sub.2O.sub.3, wherein M is one or more selected from Na, K, Ba and Ca, and 1≤x≤2.

One aspect of the present invention is a solid electrolyte which has a crystal structure attributable to a space group F-43m and contains lithium, phosphorus, sulfur, and an element A, in which the element A is a metal element having an ionic radius of more than 59 pm and 120 pm or less in 4-fold coordination and 6-fold coordination in an ion crystal.

Provided is a battery comprising a cathode, an anode, and an electrolyte layer. The electrolyte layer includes a first electrolyte layer and a second electrolyte layer. The first electrolyte layer includes a first solid electrolyte material. The second electrolyte layer includes a second solid electrolyte material which is a material different from the first solid electrolyte 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.

Provided is a battery comprising a cathode, an anode, and an electrolyte layer. The electrolyte layer includes a first electrolyte layer and a second electrolyte layer. The first electrolyte layer includes a first solid electrolyte material. The second electrolyte layer includes a second solid electrolyte material which is a material different from the first solid electrolyte 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.

A compound comprising phosphorus atoms and sulfur atoms as constituent elements and having a peak in Raman spectroscopy, the peak being attributable to a disulfide bond bonding between two phosphorus atoms.

A compound comprising phosphorus atoms and sulfur atoms as constituent elements and having a peak in Raman spectroscopy, the peak being attributable to a disulfide bond bonding between two phosphorus atoms.

A solid electrolyte: (compound A) a compound that has a crystal phase having an argyrodite-type crystal structure and that is represented by Li.sub.aPS.sub.bX.sub.c, where X is at least one elemental halogen, a represents a number of 3.0 or more and 6.0 or less, b represents a number of 3.5 or more and 4.8 or less, and c represents a number of 0.1 or more and 3.0 or less; and (compound B) a compound that is represented by LiX, where X is as defined above. The compound B has a crystallite size of 25 nm or more. The solid electrolyte preferably has a BET specific surface area of 14.0 m.sup.2/g or less.

A solid electrolyte: (compound A) a compound that has a crystal phase having an argyrodite-type crystal structure and that is represented by Li.sub.aPS.sub.bX.sub.c, where X is at least one elemental halogen, a represents a number of 3.0 or more and 6.0 or less, b represents a number of 3.5 or more and 4.8 or less, and c represents a number of 0.1 or more and 3.0 or less; and (compound B) a compound that is represented by LiX, where X is as defined above. The compound B has a crystallite size of 25 nm or more. The solid electrolyte preferably has a BET specific surface area of 14.0 m.sup.2/g or less.