Recently, the development of solid oxide fuel cell is intended to decrease the operational temperature. One of the attemp is using material which has high ionic conductivity at low temperature. LSGM is a material thats meets this criteria. Its combination with zirconia-based material may increase the chemical stability of LSGM which is still a constrain in application, due to zirconia based materials have good chemical stability after long cycle in used under high temperature. In this book, the preparation of some mixtures of zirconia-based and LSGM is explained, and continued with analysis of material properties including crystal structure, morphology, elemental analysis, ionic conductivity, and the performance of the mixtured materials as electrolyte in single fuel cell. Further analysis on impedance data of each material allows studying the contribution of grain and grain boundary conductivity to total ionic conductivity.