Tape casting fabrication and co-sintering of solid oxide "half cells" with a cathode-electrolyte porous interface

Solid oxide fuel cells in the planar anode-supported configuration were prepared by water-based tape casting and screen printing. In order to obtain a large extent of three phase boundaries (TPBs) at the electrolyte/cathode interface, a porous Yttria-Stabilized Zirconia with Yttria content equal to 10mol% (10YSZ) interlayer was inserted in the green laminate. A composite cathode was then obtained by impregnating the porous electrolyte with a (La0.8Sr0.2)MnO3 (LSM20) gel precursor and a LSM20 current collector was finally screen printed on the cathode layer. Electrochemical performances of the as-prepared cells were investigated in terms of open circuit voltage measurements, polarization and impedance spectroscopy analyses in the temperature range between 700 and 900 degrees C. For cells impregnated before the current collector sintering it was observed that the shrinkage of the LSM20 phase leads to a change in cathode/electrolyte morphology when samples are treated to 1150 degrees C. The electrochemical behaviour of cells impregnated before and after sintering at 1150 degrees C were investigated and it was observed that samples with the 10YSZ interlayer post-impregnated after the heat treatment at 1150 degrees C achieve higher power densities than pre-impregnated cells. (c) 2006 Elsevier B.V All rights reserved.