It was recalled that it had been discovered that polycrystalline Li0.34La0.51TiO2.94 exhibited an ionic conductivity of more than 2 x 10-5S/cm (direct current) at room temperature. The compound had a cubic perovskite structure with a c-parameter of 0.38710nm. By using alternating current impedance analyses, it was shown that the equivalent circuit of the sample could be divided into 2 parts: bulk crystal and grain boundary. The ionic conductivity of the bulk could be as high as 0.001S/cm at room temperature. This high conductivity was attributed to the presence of many equivalent sites for Li ions to occupy and freely move through. This compound was also easy to react with Li metal, and the electronic conductivity then became much higher than before. This was explained by assuming that a Ti ion was reduced by Li insertion into a vacant site; thus introducing an electron carrier.

Y.Inaguma, L.Chen, M.Itoh, T.Nakamura, T.Uchida, H.Ikuta, M.Wakihara: Solid State Communications, 1993, 86[10], 689-93