Ceria/Bismuth Oxide Bilayer Electrolyte Based Low-Temperature SOFCs with Stable Electrochemical Performance

In this work, we report on the fabrication and performance of anode supported cells based on gadolinium doped ceria (GDC) and stabilized bismuth oxide (xSB) bilayer electrolyte that can operate at low temperatures (450-650 degrees C). Thickness of GDC and xSB layers was varied between 23-70 mu m and 0-25 mu m, respectively. The results showed the addition of xSB layer was effective in blocking electronic conduction which increased the OCV compared to the baseline single layer GDC cell. Further, the relative and total thickness of the two layers showed a significant impact on the OCV of the cell at different temperatures with best performance obtained with cells with lower GDC thickness and higher xSB thickness. Long-term stability tests showed exceptionally low degradation rates for OCV of the bilayer GDC/xSB cells. At 650 degrees C, a GDC/xSB bilayer fuel cell showed a maximum power density and total area specific resistance (ASR) of 1.06 W/cm(2) and 0.17 Omega cm(2), respectively.