Cathode supported tubular solid oxide fuel cells with nanostructured La0.6Sr0.4Co0.2Fe0.8O3 electrocatalysts

• LSCF–YSZ cathode supported tubular SOFCs are successfully developed.
• The tubular cell has a low polarization resistance of 0.33 Ω cm2 at 750 °C.
• The tubular cell has a peak power density of 0.55 W cm−2 at 750 °C.
• It is feasible to fabricate cathode supported SOFC with the impregnation method.

Tubular solid oxide fuel cells (SOFCs) are developed with thick (∼0.50 mm) La0.6Sr0.4Co0.2Fe0.8O3 (LSCF)–(Y2O3)0.08(ZrO2)0.92 (YSZ) cathode substrates and thin (6.9 μm) film YSZ electrolytes. LSCF is introduced to the thick porous YSZ substrate by impregnating technique, resulting in nanostructured LSCF particles, which are formed at 800 °C. The relatively low sintering temperature has effectively eliminated the possible solid–state reaction, which occurs between YSZ and LSCF above 900 °C. The nanostructured electrocatalyst promotes the electrochemical activity, resulting in total interfacial polarization resistance of 0.33 Ω cm2 at 750 °C for the single cell. At the same temperature, the cell has achieved a peak power density of 0.55 W cm−2, much higher than those reported for the cathode supported tubular SOFCs (about 0.2 W cm−2). The improved performance demonstrates the feasibility of fabricating cathode supported tubular SOFCs with highly active catalysts such as LSCF, Sm0.5Sr0.5CoO3, Ba0.5Sr0.5Co0.8Fe0.2O3 and PrBaCo2O5.