The cathodic performance of selected mixed-conducting electrodes, including perovskite-type SrMn0.6Nb0.4O3 - delta, Sr0.7CeO3Mn0.9Cr0.1O3 (- delta) and Gd0.6Ca0.4Mn0.9Ni0.1O3 - delta, and Ruddlesden-Popper La2Ni0.5Cu0.5O4 (+) (delta), LaSr2Mn1.6Ni0.4O7 - delta La4Ni3 - xCuxO10 - delta (x=0-0.1) and La3.95Sr0.05Ni2CoO10 - delta was evaluated in contact with apatite-type La10Si5AlO26.5 solid electrolyte at 873-1073 K and atmospheric oxygen pressure. The electrochemical activity of porous nickelate-based layers was found to correlate with the concentration of mobile ionic charge carriers and bulk oxygen transport, thus lowering in the series La4Ni2.9Cu0.1O10 - delta > La4Ni3O10 - delta > La3.95Sr0.05Ni2CoO10 - delta and decreasing on copper doping in K2NiF4-type La2Ni1 - xCuxO4 - delta. The relatively high overpotentials of nickelate-based cathodes, varying in the range -240 to - 370 mV at 1073 K and current density of - 200 mA/cm(2), are primarily associated with surface diffusion of silica from La10Si5AlO26.5, which partially blocks the electrochemical reaction zone. As compared to the intergrowth nickelate materials, the manganite-based electrodes exhibit substantially worse electrochemical properties, in correlation with the level of oxygen-ionic and electronic conduction in Mn-containing phases. The effects of cation interdiffusion between the cell components as a performance-deteriorating factor are briefly discussed. (C) 2009 Elsevier B.V. All rights reserved.