Investigation of Gd, Ca and Nd tri-doped ceria for application in solid oxide fuel cells

Abstract

Nanosized tri-doped ceria powders with composition Ce0.8Gd0.15Ca0.05-xNdxO2-δ (CGCN, x = 0.0125, 0.025, 0.0375) were obtained by sol-gel methods. The powders were compressed into discs and sintered in air to form perspective solid electrolytes. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS) methods. XRD and SEM analyses confirm that the samples are densified and have fluorite structure after sintering at 1350°C. Among all Ce0.8Gd0.15Ca0.05-xNdxO2-δ samples, the sintered Ce0.8Gd0.15Ca0.025Nd0.025O2-δ electrolyte has the highest conductivity of 2.5 × 10−2 S/cm at 800°C and the corresponding activation energy is 0.64 eV.

Keywords

• solid oxide fuel cells
• electrolyte
• doped-ceo2
• structure
• electrical conductivity