Optimizing solid oxide fuel cell cathode processing route for intermediate temperature operation

For Solid Oxide Fuel Cells (SOFCs) to become an economically attractive energy conversion technology suitable materials which allow operation at lower temperatures, while retaining cell performance, must be developed. At the same time, the cell components must be inexpensive - requiring both low-priced raw material and cost-effective production techniques. In this work the perovskite-type La0.6Ca0.4Fe0.8Ni0.2O3 (LCFN) oxide has been used in order to optimize intermediate temperature SOFC cathode processing route. The advantages this material presents arise from the low temperature powder calcination (similar to 600 degrees C) and electrode sintering (similar to 800 degrees C) of LCFN electrodes, making them a cheaper alternative to conventional SOFC cathodes. An electrode polarization resistance as low as 0.10 Omega cm(2) at 800 degrees C is reported, as determined by impedance spectroscopy studies of symmetrical cells sintered at a range of temperatures (800-1000 degrees C). Scanning Electron Microscopy (SEM) studies revealed porous electrode microstructures, even when sintered at a temperature of just 800 degrees C. The competitive performance of the electrodes sintered at low temperatures, combined with the low raw material cost, make these electrodes an excellent potential choice for SOFC cathodes. In this work a new cathode processing technique is presented which provides a more economical, lower temperature SOFC production route with no detrimental effect on device efficiency. (C) 2012 Elsevier Ltd. All rights reserved.