High performance praseodymium nickelate oxide cathode for low temperature solid oxide fuel cell

The praseodymium nickelate oxide Pr sub(2)NiO sub(4+) delta a mixed conducting oxide with the K sub(2)NiF sub(4)-type structure, was evaluated as cathode for low temperature solid oxide fuel cells (T = 873 K). The electrochemical performance of the cathode has been improved by optimization of the microstructure of the porous cathode combined with the use of a ceria barrier layer in between the cathode and zirconia electrolyte. Both low polarization and ohmic resistances were obtained using Pr sub(2)NiO sub(4+) delta powders with a median particle size of 0.4 mu m, and sintering the screen printed layer at a sintering temperature of about 1353 K for 1 h. These manufacturing conditions resulted in a cathode microstructure with well established connections between the cathode particles and good adhesion of the cathode on the electrolyte. Full-sized anode supported cells have been manufactured using the same process conditions for the Pr sub(2)NiO sub(4+) delta cathode and tested. The best results were obtained when using a dense Ce sub(0.8)Gd sub(0.2)O sub(1.9) (20CGO) barrier layer. While a complete optimization of the cell preparation has not yet been achieved, the electrochemical performances of anode supported cells with Pr sub(2)NiO sub(4+) delta are higher than those with the well known state-of-the-art La sub(0.6)Sr sub(0.4)Fe sub(0.8)Co sub(0.2)O sub(3-) delta (LSFC) material.