Structure and ionic conductivity of Lix(MeO)4Me30O90 (Me = NbV, WVI)

Abstract The compound Li x (MeO) 4 Me 30 O 90 (Me = Nb V , W VI ) has been prepared and investigated by X-ray powder and electron diffraction techniques as well as by measurements of complex impedance. The structure is of the tripled tetragonal tungsten bronze type with one third of the pentagonal tunnels filled with equal numbers of Me and 0 atoms. The conductivity at 300°C is 0.20 and 0.25 ohm −1 m −1 for sintered samples with x equal to 2 and 4, respectively. The location and probable routes of transport of the lithium ions are discussed.