Lithium-containing garnet crystal and all-solid-state lithium ion secondary battery

Abstract

There are provided a lithium-containing garnet crystal high in density and ionic conductivity, and an all-solid-state lithium ion secondary battery using the lithium-containing garnet crystal. The lithium-containing garnet crystal has a chemical composition represented by Li7-xLa3Zr2-xTaxO12 (0.2≦x≦1), and has a relative density of 99% or higher, belongs to a cubic system, and has a garnet-related structure. The lithium-containing garnet crystal has a lithium ion conductivity of 1.0×10−3 S/cm or higher. Further, this solid electrolyte material has a lattice constant a of 1.28 nm≦a≦1.30 nm, and lithium ions occupy 96h-sites in the crystal structure. The all-solid-state lithium ion secondary battery has a positive electrode, a negative electrode and a solid electrolyte, and the solid electrolyte is constituted of the lithium-containing garnet crystal according to the present invention.

Dependencies are inferred from the claim text.