Enhanced electrical conductivity of ceria electrolyte doped with samarium (Ce<inf>0.8− x</inf> Zr<inf>x</inf> Sm<inf>0.2</inf> O<inf>2−δ</inf> ) for solid oxide fuel cells

Abstract

To affluence the ionic conductivity enhancement in Cerium Oxide (CeO2) for low temperature solid oxide fuel cells (LT-SOFCs), we report synthesis of Zr substituted, Samarium doped Ceria (SDC) via chemical procedure. Substitution of Zr has assisted the stabilizing of majority Ceria as Ce4+ and improved the ionic conductivity considerably. The cubic fluorite structure of CeO2 was supported by Raman spectroscopy and X-ray diffraction (XRD). Particle’s morphology is studied using SEM, TEM which revealed size of CeO2 as 20 nm. Valence state of cations and concentration of Ce4+ are proven through X-ray photo electron spectroscopy (XPS). This result confirms 50% upsurge in tetravalent Cerium concentration (from 56 to 84%) which influences the ionic conductivity. The x = 0.075 composition revelations greater ionic conductivity of 0.528 × 10–1(S cm−1) at 750 °C in comparison with other ‘x’ configurations. The substitution of Zr4+ in SDC stabilizes the cubic fluorite structure and promotes oxygen vacancies enhancing ionic conducting nature. The elevated ionic conductivity value and stability of Ce4+ the present work proposes that the prepared materials are promising ionic conductors.