| abstract |
A novel solid electrolyte material having high density and ionic conductivity, and an all-solid-state lithium ion secondary battery using the solid electrolyte material are provided. The solid electrolyte material has a chemical composition expressed as Li 7-3x Ga x La 3 Zr 2 O 12 (0.08≤x<0.5), a relative density of 99% or more, and belongs to the cubic system, space group I-43d, , has a garnet-like structure. This solid electrolyte has a lithium ion conductivity of 2.0×10 -3 S/cm or more. In addition, this solid electrolyte material has a lattice constant a of 1.29 nm ≤ a ≤ 1.30 nm, and lithium ions occupy 12a, 12b, and two types of 48e sites in the crystal structure, and gallium occupies 12a and 12b sites. do. An all-solid-state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, and the solid electrolyte is composed of the solid electrolyte material of the present invention. |