Comparison of electrolyte fabrication techniques on the performance of anode supported solid oxide fuel cells


Onbilgin S., Timurkutluk B., Timurkutluk C., Celik S.

International Journal of Hydrogen Energy, vol.45, no.60, pp.35162-35170, 2020 (Journal Indexed in SCI Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 45 Issue: 60
  • Publication Date: 2020
  • Doi Number: 10.1016/j.ijhydene.2020.01.097
  • Title of Journal : International Journal of Hydrogen Energy
  • Page Numbers: pp.35162-35170
  • Keywords: Dip coating, Electrolyte, Screen printing, Solid oxide fuel cell, Tape casting, Yttria stabilized zirconia

Abstract

© 2020 Hydrogen Energy Publications LLCA comparison of three solid oxide electrolyte fabrication processes, namely dip coating, screen printing and tape casting, for planar anode supported solid oxide fuel cells (SOFCs) is presented in this study. The effect of sintering temperature (1325–1400 °C) is also examined. The anode and cathode layers of the anode-supported cells, on the other hand, are fabricated by tape casting and screen printing, respectively. The quality of the electrolytes is evaluated via performance measurements, impedance analyses and microstructural investigations of the cells. It is found that the density of the electrolyte increases with the sintering temperatures for all fabrication methods studied. The results also show that with the process and fabrication parameters considered in this study, both dip coating and screen printing do not yield a desired dense electrolyte structure as proven by open circuit potentials measured and SEM photos. The cells with tape cast electrolytes, on the other hand, provide the highest performances regardless of the electrolyte sintering and cell operating temperatures. The best peak performance of 0.924 W/cm2 is obtained from the cell with tape cast electrolyte sintered at 1400 °C. SEM investigations and measured open circuit potentials reveal that almost fully dense electrolyte layer can be obtained with a tape cast electrolyte particularly sintered at temperatures higher than 1350 °C. Impedance analyses indicate that the main reason behind the significantly higher performances is due to not only increased electrolyte density but a decrease in the interface resistance of the anode functional and electrolyte layer is also responsible. This can be explained by the load applied during the lamination step in the fabrication of the tape cast electrolyte, providing better powder compaction and adhesion.