Elucidating the nature of grain boundary resistance in lithium lanthanum titanate

Solid electrolytes for all-solid-state batteries are generating remarkable research interest as a means to improve the safety, stability and performance of rechargeable batteries.

Solid State Reaction Synthesis and Characterization of Lithium Lanthanum Titanate Lithium-Ion Conducting Solid Electrolyte with Different Li to La Content

Lithium Lanthanum Titanate, Li3xLa(2/3)-x□(1/3)-2xTiO3, with three different compositions of (i) x = 0.097 (Li0.29La0.57TiO3), (ii) x = 0.117 (Li0.35La0.55TiO3), and (iii) x = 0.167 (Li0.50La0.50TiO3) were prepared via solid state reaction synthesis sintered at 1150 °C for 36 hours. X-ray diffraction (XRD) analysis revealed that all samples can be indexed to a cubic perovskite structure with lattice parameter a of about 3.86 Å. Morphological analysis using SEM showed that the samples are relatively dense and the calculated relative density of the LLTO samples range from about 94% to as high as 99% with increasing trend as Li content increases. Room temperature conductivity and its temperature dependence up to 120 °C were investigated. LLTO sample with x =0.117 revealed the highest total ionic conductivity at room temperature of about 1.69 x 10-03 S/cm which can be a promising solid electrolyte for an all-solid-state lithium-ion batteries.