Low-temperature solid oxide fuel cells with novel La0.6Sr0.4Co0.8Cu0.2O3-δ perovskite cathode and functional graded anode

The perovskite La0.6Sr0.4Co0.8Cu0.2O3-delta (LSCCu) oxide is synthesized by a modified Pechini method and examined as a novel cathode material for low-temperature solid oxide fuel cells (LT-SOFCs) based upon functional graded anode. The perovskite LSCCu exhibits excellent ionic and electronic conductivities in the intermediate-to-low-temperature range (400-800 C). Thin Sm0.2Ce0.8O1.9 (SDC) electrolyte and NiO-SDC anode functional layer are prepared over macroporous anode Substrates composed of NiO-SDC by a one-step dry-pressing/co-firing process. A single cell with 20 mu m thick SDC electrolyte on a porous anode support and LSCCu-SDC cathode shows peak power densities of only 583.2 mW cm(-2) at 650 degrees C and 309.4 mW cm(-2) for 550 degrees C While a cell with 20 mu m thick SDC electrolyte and ail anode functional layer on the macroporous anode substrate shows peak power densities of 867.3 and 490.3 mW cm(-2) at 650 and 550 degrees C, respectively. The dramatic improvement of cell performance is attributed to the much improved anode microstructure that is confirmed by both SEM observation and impedance spectroscopy The results indicate that LSCCu is a very promising cathode material for LT-SOFCs and the one-step dry-pressing/co-firing process is a suitable technique to fabricate high performance SOFCs. (C) 2009 Elsevier B.V. All rights reserved.