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 Å. The bulk and total lithium ion conductivities of Li6La3ZrTaO12 at 25 °C were 2.5 × 10−4 S cm−1 and 1.8 × 10−4 S cm−1, respectively; the activation energy was about 0.42 eV in the temperature range 298–450 K.

► A garnet-related oxide Li6La3ZrTaO12 was obtained by solid-state reaction.
► The bulk and total Li+-ion conductivities at 25 °C are 2.5 × 10−4 and 1.8 × 10−4 S cm−1.
► The activation energy is about 0.42 eV in the temperature range 298–450 K.
► It is stable on contact with a metallic lithium anode.