Molten-salt synthesis of oxyapatite La9.33Si6O26 powders as electrolytes for intermediate temperature solid oxide fuel cells

✍ Scribed by Huang, Zhaoxiang ;Li, Buyin ;Liu, Jia

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 437 KB
• Volume: 207
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200925605

✦ Synopsis

Abstract

Lanthanum silicate oxy‐apatites are thought of as ytrria‐stabilized zirconia substitutes in intermediate temperature solid oxide fuel cells. Lanthanum silicate oxy‐apatite powders La~9.33~Si~6~O~26~ are successfully synthesized at lower temperature by a molten‐salt method. X‐ray diffraction, scanning electron microscopy, and precision impedance analysis used to characterize the structure, appearance, and conductivity of La~9.33~Si~6~O~26~. The results indicate that the apatite phase has been synthesized. The synthesis method decreases the synthesis temperature by about 300 °C in comparison to the conventional solid‐state reaction route and obtains homogeneous and nanosize powders. Dense ceramics have been prepared at sintering temperatures around 1450 °C. The used of molten‐salt powders allows a decrease of the dense ceramic pellet sintering temperature of about 200 °C. The ceramic pellets sintering at 1550 °C for 4 h have a relative density of 92% and an electrical conductivity of 1.1 × 10^−3^ S cm^−1^ at 700 °C, higher than the some reported for the solid‐state synthesis method and the sol–gel method.