Microstructural effects on the superionic conductivity of a lithiated glass-ceramic

Three different formulations of 14 Li(2)O(.)9 Al(2)O(3)(.)38 TiO(2)(.)39 P2O5 composition (LATP) were melted, cast and crystallized. As-east glass was characterized by differential scanning calorimetry which exhibited a distinct and strong exothermic peak around 680 degrees C. The peak was attributed to the crystallization of the glass. The crystallized glass (glass-ceramic) was further characterized by X-ray diffraction which showed the existence of Li1+xAlxTi2-x(PO4)(3) (x similar or equal to 0.3)as the primary phase mixed with a small concentration of AlPO4 and an unidentified phase. The scanning electron micrographs revealed the presence of the primary crystalline phase with an average grain size of 1 mu m. Electrical characterization by AC impedance spectroscopy revealed grain and grain boundary contributions to the total conductivity. The effect of specimen processing parameters on conductivity is also investigated and discussed. (c) 2006 Elsevier B.V. All rights reserved.