New lithium-ion conducting perovskite oxides related to (Li, La)TiO3

We describe the synthesis and lithium-ion conductivity of new perovskite-re lated oxides of the formulas, LiCa(1.65)square 0.35Ti1.3B1.7O9 (B = Nb, Ta) (I, II), LiSr2Ti2.5W0.5O9 (III) and LiSr(1.65)square 0.35Ti2.15W0.85O9 (IV ). Oxides I and II crystallize in orthorhombic (GdFeO3-type) structure, whi le oxides III and IV possess cubic symmetry. All of them exhibit significan t lithium-ion conduction at high temperatures, the highest conductivity of similar to 10(-2) S/cm at 800 degreesC among the oxides is exhibited by the composition IV. The results are discussed in the light of previous work on lithium-ion conducting perovskite oxides containing d(0) cations.