On the La(2/3-x)Li(3x)TiO(3)/Al(2)O(3) composite solid-electrolyte for Li-ion conduction

An effective ceramic processing route including tape casting and relatively low-temperature calcination has been adopted to fabricate La(0.56)Li(0.33)TiO(3) (LLTO)/Al(2)O(3) composite electrolytes. Correlation among additional amount of Al(2)O(3), microstructure and Li-ion conductivity of the composites is examined and evaluated. What is most interesting from X-ray diffraction and transmission electron microscopy is that LiAl(5)O(8) phase is found to form in the LLTO/Al(2)O(3) composites during calcination. The present study indicates that the presence of LiAl(5)O(8) has a beneficial effect of increasing ionic conductivity and decreasing activation energy. It was observed that the LLTO/10wr% Al(2)O(3) composite electrolyte exhibits a higher conductivity at bulk (~6 times) and grain boundary (~3 times) compared to pure LLTO at room temperature. An Arrhenius temperature dependence of Li-ion motion in this composite electrolyte is obtained, displaying low activation energy of 0.17 and 0.37 eV for bulk and grain boundary conduction, respectively.