The neodymium-deficient nickelate Nd1.95NiO4+ı, 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® cells. Using a layer of strontium doped lanthanum cobaltite as current collector, a current density of 1.31Acm−2 (at 0.70V) was obtained at 800 ◦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.