Anode-supported SOFCs with Y ₂O ₃-doped Bi ₂O ₃/Gd ₂O ₃-Doped CeO ₂ composite electrolyte film

Anode-supported solid oxide fuel cells (SOFCs) with a bilayered yttria-doped bismuth (YDB) and gadolinia-doped ceria (GDC) composite electrolyte film were developed. The cell with an YDB/GDC composite electrolyte film (84 μm GDC+16 μm YDB) showed an increase of 68-96 mV in open-circuit voltage in the operating temperature range of 700-500°C, compared with that with a single GDC electrolyte film (∼99 μm). Using Pt as the cathode, the cell with the YDB/GDC composite electrolyte also showed much lower electrode polarization resistance than that with the single GDC electrolyte and almost the same ohmic resistance as the latter. As a result of the combined effects of these factors, the cell with an YDB/GDC composite electrolyte can achieve 0.6∼1.5 times higher maximum power density than that with a single GDC electrolyte in the operating temperature range of 700-500°C.