Abstract
La-doped CeO_2 nanoparticles of composition Ce_(1-x)La_xO_(2-δ) (0 ≤ x ≤ 0.1) have been studied here as prospective electrolytes for intermediate temperature solid oxide fuel cells (IT-SOFCs). They were synthesized by auto-combustion method and the powder samples were calcined at 700 °C to get ultrafine nanocrystalline particles. They were characterized by XRD, Raman, FTIR, XPS, DRS, FESEM/EDX, particle size analyzer and ac-impedance techniques. Ionic conductivity was measured from 350 - 750 °C. The Ce_(0.90)La_(0.10)O_(2-δ) (0.1 LDC) and Ce_(0.95)La_(0.05)O_(2-δ) (0.05 LDC) showed a maximum conductivity of 8.89 ×10~(-3) and 8.32 ×10~(-3) S cm~(-1) at 700 °C, respectively. The σt of 0.1 LDC = 1.01 ×10~(-2) S cm~(-1) at 750 °C. The activation energy of 0.1 LDC and 0.05 LDC was found to be 0.70 eV and 0.87 eV, respectively. These values are higher than those reported for La-doped CeO_2 in literature. The SOFC performance with 0.05 LDC as electrolyte showed open circuit voltage of 0.81 V and maximum power density of 41 mW cm~(-2) at 650 °C using hydrogen as fuel.
NSTL
Elsevier