Comparative study of the nano-composite electrolytes based on samaria-doped ceria for low temperature solid oxide fuel cells (LT-SOFCs)

• Ceria-based electrolyte materials have great potential.
• One-step co-precipitation method.
• The power density was achieved 484 mW/cm2 of LNK-SDC electrolyte at 570 °C.
• The LNK-SDC nanocomposite electrolyte exhibits 0.098 Scm−1 ionic conductivity in air atmosphere.
• The low activation energies of the nanocomposite electrolyte 0.34 eV was calculated.

Ceria-based electrolyte materials have great potential in low and intermediate temperature solid oxide fuel cell applications. In the present study, three types of ceria-based nano-composite electrolytes (LNK-SDC, LN-SDC and NK-SDC) were synthesized. One-step co-precipitation method was adopted and different techniques were applied to characterize the obtained ceria-based nano-composite electrolyte materials. TGA, XRD and SEM were used to analyze the thermal effect, crystal structure and morphology of the materials. Cubic fluorite structures have been observed in all composite electrolytes. Furthermore, the crystallite sizes of the LN-SDC, NK-SDC, LNK-SDC were calculated by Scherrer formula and found to be in the range 20 nm, 21 nm and 19 nm, respectively. These values emphasize a good agreement with the SEM results. The ionic conductivities were measured using EIS (Electrochemical Impedance Spectroscopy) with two-probe method and the activation energies were also calculated using Arrhenius plot. The maximum power density was achieved 484 mW/cm2 of LNK-SDC electrolyte at 570 °C using the LiCuZnNi oxide electrodes.