Tape casting fabrication and co-sintering of solid oxide " half cell " 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°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°C. The electrochemical behaviour of cells impregnated before and after sintering at 1150°C were investigated and it was observed that samples with the 10YSZ interlayer post-impregnated after the heat treatment at 1150°C achieve higher power densities than pre-impregnated cells.