SULFIDE SOLID ELECTROLYTE FOR ALL-SOLID-STATE SECONDARY BATTERY AND ALL-SOLID-STATE SECONDARY BATTERY INCLUDING THE SAME

The present invention refers to a sulfide solid electrolyte for all-solid-state secondary batteries, wherein the sulfide solid electrolyte has an argyrodite-type crystal structure and the sulfide solid electrolyte is a compound represented by Formula 1 below: Formula 1 LiPSX in Formula 1, X is fluorine (F), chlorine (Cl), bromine (Br), or iodine (I), and 4.7