Fully solid-state lithium secondary battery electrolyte material, preparation method thereof and fully solid-state lithium secondary battery

The invention provides a fully solid-state lithium secondary battery electrolyte material, which contains Li2S, a first sulfide, a second sulfide and a dopant, wherein the first sulfide is GeS and/or GeS2; the second sulfide is one or more of FeS, FeS2, SiS2, P2S5, B2S3, CeS2 and Al2S3; and the dopant is a lithium salt or an oxide capable of forming raw acid. According to the fully solid-state lithium secondary battery electrolyte material, the lithium ion conductivity of the fully solid-state lithium secondary battery electrolyte material at room temperature is increased by using the first sulfide, the second sulfide and the dopant. Experiments show that the lithium ion conductivity of the fully solid-state lithium secondary battery electrolyte material reaches up to 10 S.cm at the room temperature, the conductivity is better, and the application is facilitated. In addition, the lithium ion conductivity of the fully solid-state lithium secondary battery electrolyte material has better electrochemical stability. The invention provides a preparation method of the lithium ion conductivity of the fully solid-state lithium secondary battery electrolyte material and a fully solid-state lithium secondary battery.