(La0.8Sr0.2)(0.98)Fe0.98Cu0.02O3-delta can be sintered directly onto YSZ (without the need for a protective ceria interlayer). Though subject to an extended "burn-in" period (similar to200 h), anode-supported YSZ cells using the Cu-doped LSF achieve power densities ranging from 1.3 to 1.7 W/cm(2) at 750 degreesC and 0.7 V. These cells have also demonstrated 500 h of stable performance. The results are somewhat surprising given that XRD indicates an interaction between (La0.8Sr0.2)(0.98)Fe0.98Cu0.02O3-delta and YSZ resulting in the formation of strontium zirconate and/or monoclinic zirconia. The amount and type of reaction product was fount to be dependent on cathode and electrolyte powder precalcination temperatures.