Solid electrolyte material of conducting lithium ion, battery device using the solid electrolyte material and all-solid lithium secondary battery provided with the battery device

1. A solid electrolyte material comprising a sulfide-based lithium-ion conductor, α-alumina, and an organic binder constituted of a resin material as a main constituent material thereof,

wherein the sulfide-based lithium-ion conductor is Li 2 S—GeS 2 —P 2 S 5 , Li 2 S—P 2 S 5 , or Li 2 S—P 2 S 5 —LiI, and

wherein the resin material is constituted of at least one of polyamide or polyimide as a main component thereof, and

wherein an amount of the α-alumina contained in the electrolyte material is 5 wt % at a ratio by weight to the sulfide-based lithium-ion conductor.

2. The solid electrolyte material as claimed in claim 1 , wherein the sulfide-based lithium-ion conductor is constituted of a crystalline material, an amorphous material or a mixture material of the crystalline material and the amorphous material.

3. The solid electrolyte material as claimed in claim 1 , wherein the sulfide-based lithium-ion conductor contains a semiconductor as a component thereof.

4. The solid electrolyte material as claimed in claim 1 , wherein the solid electrolyte material is formed by mixing the sulfide-based lithium-ion conductor and α-alumina with a ball mill.

5. A battery device, comprising: a pair of electrodes; and an electrolyte layer provided between the pair of electrodes; wherein the solid electrolyte material defined in claim 1 is contained in the electrolyte layer.

6. An all-solid lithium secondary battery provided with the battery device defined in claim 5 .