Role of Electronic Conduction in Stability of Solid Oxide Electrolyzer Cells (SOEC)

摘要

A series of control experiments were performed to explore the role of electronic conduction on the stability of SOECs using pure 8YSZ and CeO_2-doped 8YSZ as electrolytes. Under similar conditions, the measured polarization resistances on the 8YSZ supported cells either increased or decreased after passing current for about 24 h, while the polarization resistance remained fairly stable on the 5Ce8YSZ supported cells. The measured potential using an embedded Pt probe at the center of a 8YSZ supported cell started to fluctuate after passing current for ～50 h and reached the maximum amplitude at about 130 to 150 h. By contrast, the measured potential at the probe did not show fluctuations on a 8Ce8YSZ supported cell. The measured oxygen content after passing current through a 8YSZ supported cell was higher near the positive electrode and lower near the negative electrode. By contrast, the oxygen concentration throughout a 5Ce8YSZ supported cell was unchanged even after passing current.