Sequential-infiltration of Ce and Ni in NiO-YSZ fuel electrode for tubular type solid oxide reversible cells (SORC) using LaGaO₃ electrolyte film

NiO-Y₂O₃ stabilized ZrO₂ (YSZ) tubular type cell using La_0.9Sr_0.1Ga_0.8Mg_0.2O_3−δ electrolyte film was prepared by dip-coating method. Effects of Ce infiltration or Ce, Ni sequential-infiltration into NiO-YSZ substrate were studied and it was found that Ce infiltration after Ni is highly effective for increasing the cell performance and the stability in fuel cell and electrolysis mode at 873 K in spite of decrease in performance by simple Ni infiltration. Cyclic operation of the fuel cell and electrolysis of LSGM tubular cell using Ce or Ce[sbnd]Ni sequential-infiltrated NiO-YSZ substrate was measured at 873 K using 17% steam-25%H₂ in Ar as fuel. After 100 cycles at ±0.1 A cm⁻², OCV was almost the same with the initial value. The terminal potential in SOFC operation became slightly lower with increasing cycle number in case of simple Ce infiltration. The main reason for degradation during cyclic performance seems to be assigned to the increased fuel electrode overpotential. However, degradation rate is much decreased by Ce[sbnd]Ni sequential-infiltration.