SULFIDE SOLID ELECTROLYTE, AND ELECTRODE MIXTURE, SOLID ELECTROLYTE LAYER, AND SOLID BATTERY USING SAME

A sulfide solid electrolyte according to the present invention contains a compound that has a crystal phase having an argyrodite-type crystal structure and that is represented by LiaPSbXc, 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. The sulfide solid electrolyte has a ratio of ALi / (ALi + AP + AS + AX) to a specific surface area (m2g-1) of 3.40 (m-2g) or more, where ALi represents the amount of lithium (atom%) quantitatively determined from the Li 1s peak, AP represents the amount of phosphorus (atom%) quantitatively determined from the P 2p peak, As represents the amount of sulfur (atom%) quantitatively determined from the S 2p peak, and Ax represents the amount of halogen (atom%) quantitatively determined from the halogen peak, the peaks being exhibited in X-ray photoelectron spectroscopy (XPS).