Low temperature synthesis and ionic conductivity of the epitaxial Li0.17La0.61TiO3 film electrolyte

Epitaxial thin films of the lithium ionic conductor Li0.17La0.61TiO3 have been successfully synthesized on Al2O3(0001) and Nb:SrTiO3(001) substrates at working temperatures below 750 degrees C using pulsed laser deposition. The application of high laser fluence in conjunction with low oxygen pressure was identified as the key to obtaining highly crystalline Li0.17La0.61TiO3 films. The use of low temperatures prevents the loss of lithium during the deposition process and generates films with no compositional deviation from the target, as confirmed by chemical analyses. The Li0.17La0.61TiO3 film deposited on Al2O3(0001) exhibits a high total ionic conductivity of 3.76 x 10(-4) S cm(-1) at room temperature, which is comparable to the bulk ionic conductivity of polycrystalline Li0.18La0.61TiO3. The low temperature synthetic process described herein should allow the use of new configurations to fabricate electrode-electrolyte interfaces for use in high power all solid-state batteries incorporating Li0.17La0.61TiO3 as the solid electrolyte.