Improvement of Li-ion conductivity in A-site disordering lithium-lanthanum-titanate perovskite oxides by adding LiF in synthesis

La0.56-yLi0.33TiO3-3yF3y (y = 0.017, 0.05) were prepared by a conventional solid-state reaction from a mixture of La2O3, LiCO3, TiO2. and 10% excess LiF. The variation of the lattice parameter with increase of y value in La0.56-yLi0.33TiO3-3yF3y was different from that in conventional lithium-lanthanum-titanate series perovskite oxides, La0.56-yLi0.33+3yTiO3. Bulk Li-ion conductivities of the La0.56-yLi0.33TiO3-3yF3y are higher than those of La0.56-yLi0.33+3yTiO3. Li-ion conductivity of La0.56-yLi0.33TiO3-3yF3y (y=0.017) was 2.30 x 10(-3) S cm(-1) at 30 degrees C, which is, to our knowledge, one of the highest Li-ion conductivities in the oxide compounds. (c) 2008 Elsevier B.V. All rights reserved.