Ceria-doped electrolytes have been extensively studied, because they are promising candidates for intermediate temperature solid oxide fuel cells (ITSOFC). In this work, several relevant aspects, such as powder synthesis, small additive effects, reactivity of electrode/electrolyte and interface microstructure were described. The combustion synthesis is a really suitable synthesis route to achieve, at low temperatures, finely, homogeneous and reactive powders for ceria based electrolytes. The presence of small amounts of titania is beneficial, since it produces a significant reduction of the grain boundary resistance. On the other hand, the reactivity of the ceria electrolyte against lanthanum-NiO perovskites at high temperatures (1475 degreesC), enhances both the LaNiO3-delta decomposition and the diffusion of Ni and La ions as is noted in the reactivity analysis.