Lithium-lanthanum-titanium oxide sintered material, solid electrolyte containing the oxide, lithium air battery and all-solid lithium battery including the solid electrolyte, and method for producing the lithium-lanthanum-titanium oxide sintered material

摘要

A lithium-lanthanum-titanium oxide sintered material has a lithium ion conductivity 3.0×10⁻⁴ Scm⁻¹ or more at a measuring temperature of 27° C., the material is described by one of general formulas (1-a)La_xLi_2-3xTiO₃-aSrTiO₃, (1-a)La_xLi_2-3xTiO₃-aLa_0.5K_0.5TiO₃, La_xLi_2-3xTi_1-aM_aO_3-a, and Sr_x-1.5aLa_aLi_1.5-2xTi_0.5Ta_0.5O₃ (0.55≦x≦0.59, 0≦a≦0.2, M=at least one of Al, Fe and Ga), and concentration of S is 1500 ppm or less. The material is obtained by sintering raw material powder mixture having S content amount of 2000 ppm or less in the entirety of raw material powders for mixture, that is, titanium raw material, lithium raw material, and lanthanum raw material.