In this paper, three composite electrolytes (Ce_0.8Sm_0.2O_1.9/Na₂CO₃) SDC, (Ce_0.8Gd_0.2O_1.9/Na₂CO₃) GDC and (La_0.8Sr_0.2Ga_0.8Mg_0.2O_3−δ/Na₂CO₃)LSGM nanocomposite electrolytes have been studied, also see the effect of Na₂CO₃, present as second phase, and effect of Ni support, sintering and pressure for dry pressing for fuel cell performance. The electrolytes were prepared through co-precipitation method. Different techniques were used to characterize the prepared electrolytes. The crystal structures were determined using x-ray diffraction (XRD) and structural morphologies were analyzed through scanning electron microscopy (SEM). The four probe dc conductivity and two probe AC impedance analysis were carried out in open air. The fuel cell performance was determined with and without Nickel support on anode side which resulted in a considerable difference in obtained peak power densities. It is suggested that prepared electrolytes can find potential applications in low temperatures Solid Oxide Fuel Cells (LT-SOFCs).

Key words: nanocomposite, LTSOFCs, Crystal structure, SDC, Sintering