METHOD FOR PREPARING SULFIDE-BASED SOLID ELECTROLYTE, SULFIDE-BASED SOLID ELECTROLYTE PREPARED BY THE METHOD AND ALL-SOLID-STATE LITHIUM SECONDARY BATTERY INCLUDING THE SULFIDE-BASED SOLID ELECTROLYTE

The present invention relates to a method for preparing a sulfide-based solid electrolyte, a sulfide-based solid electrolyte prepared by the method, and an all-solid-state lithium secondary battery including the sulfide-based solid electrolyte. The method of the present invention includes a) mixing LiS with PSto prepare a mixed powder, b) placing the mixed powder, an ether, and stirring balls in a container, sealing the container, followed by stirring to prepare a suspension, and c) stirring the suspension under high-temperature and high-pressure conditions to prepare sulfide-based solid particles.