The neodymium-deficient nickelate Nd1.95NiO4+delta mixed conducting K2NiF4-type oxide, was evaluated as cathode for solid oxide fuel cells. The electrochemical properties were investigated on planar Ni-YSZ anode-supported SOFC based on co-tape casted and co-fired HTceramix (R) cells. Using a layer of strontium doped lanthanum cobaltite as current collector, a current density of 1.31 A cm(-2) (at 0.70V) was obtained at 800 degrees C using hydrogen fuel with small single cells, after optimizing the cathode sintering temperature. Impedance spectroscopy measurements were performed: the different resistive contributions and the values of the corresponding equivalent capacities are discussed. (C) 2008 Elsevier B.V. All rights reserved.