Properties of La2-xPrxNiO4 cathode for intermediate-temperature solid oxide fuel cells

A series of K2NiF4-type compounds, La2-xPrxNiO4 (x = 0, 0.6, 1.0, 1.4, and 2.0), were synthesized by solid state reaction for use as cathodes in an intermediate-temperature (500-700 degrees C) solid oxide fuel cell (IT-SOFC). La(2-x)Pr(x)Nia(4) (x = 0 and 0.6) crystallize in the Fmmm space group, while La2-xPrxNiO4 (x = 1.0, 1.4, and 2.0) belong to the Bmab space group. The electrical conductivity increased by Pr doping and La2-xPrxNiO4 (x = 0.6, 1.0, and 1.4) exhibited electrical conductivities similar to one another while Pr2NiO4 had the highest. Single test-cells consisting of samarium oxide doped ceria (SDC) as an electrolyte, Ni-SDC cermet as an anode and La2-xPrxNiO4 as a cathode, were fabricated for measurements of cell performance at 500-700 degrees C. Current interruption measurements revealed that the overpotential losses mainly decreased with increasing Pr content. Pr2NiO4 was found to exhibit the best cathode characteristics; maximum lest-cell power densities of 14.1, 45.1, and 104.4 mW/cm(2) were obtained at 500, 600, and 700 degrees C, respectively. (C) 2011 The Ceramic Society of Japan. All rights reserved.