High lithium ion conduction in garnet-type Li6La3ZrTaO12

The garnet-related oxide with general formula Li6La3ZrTaO12 was prepared by conventional solid-state reaction. X-ray diffraction (XRD) and AC impedance were used to determine phase formation and the lithium-ion conductivity. The structures were refined by the Rietveld method from powder X-ray diffraction data. Li6La3ZrTaO12 is cubic and crystallizes in the space group Ia-3d with room-temperature lattice parameter a = 12.8873 angstrom. The bulk and total lithium ion conductivities of Li6La3ZrTaO12 at 25 degrees C were 2.5 x 10(-4) S cm(-1) and 1.8 x 10(-4) S cm(-1), respectively; the activation energy was about 0.42 eV in the temperature range 298-450 K. (C) 2011 Elsevier B.V. All rights reserved.