PROPERTIES OF LA0.6SR0.4CO0.2FE0.8O3-DELTA (LSCF) DOUBLE-LAYER CATHODES ON GADOLINIUM-DOPED CERIUM OXIDE (CGO) ELECTROLYTES - I - ROLE OF SIO2

Investigations using Gd-doped CeO2 electrolytes containing different l evels of SiO2, in combination with La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) electrodes, have shown that the SiO2 can influence both the electroly te and cathode resistivities. The cathode resistivity, as measured by AC impedance spectroscopy, was further reduced by fabricating an inter mediate thin dense LSCF layer at the electrolyte/electrode interface. Etching the electrolyte surface to eliminate the influence of SiO2, an d using the thin dense interfacial layer, made it possible to obtain c athode area specific resistivities (ASR) as low as 0.5 Omega cm(2) at 520 degrees C.