Effect of sintering temperature on surface morphology and electrical properties of samarium-doped ceria carbonate for solid oxide fuel cells

The effects of sintering temperature on the surface morphology, roughness, and electrical properties of samarium-doped ceria (SDC)-carbonate (SDCC) composite electrolyte were examined. SDCC composite pellets were fabricated and sintered at various temperatures ranging from 500 degrees C to 650 degrees C. Brunauer-Emmett-Teller technique and atomic force microscopy were used to investigate the surface area and surface roughness of the composite materials, respectively. Conductivity measurements using impedance spectroscopy were conducted from 350 degrees C to 550 degrees C. The specific surface area of the pure SDC powder decreased from 8.85 m(2)/g to 4.24 m(2)/g after the carbonate phase was incorporated into the SDC phase with increasing particle size. The composite pellet sintering temperature affected the continuity between the two phases [SDC and (Li/Na) carbonate], roughness, mean particle size, and conductivity of the composite electrolyte. A fully dense SDCC composite electrolyte pellet sintered at 550 degrees C exhibited a maximum ionic conductivity of 0.077 S/cm at 550 degrees C. In addition, 550 degrees C was the minimum sintering temperature to achieve good wetting between the two phases, moderate particle size, low surface roughness, and high ionic conductivity. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.