Nanoparticles Infiltration into SOFC Cathode Backbones

Abstract

Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFCs) with yttrium stabilized zirconia (YSZ) electrolyte were fabricated by the impregnation of Sm0.2Ce0.8O2-δ (SDC), Sm0.5Sr0.5CoO3-δ (SSC), CeO2, Nd1.95NiO4+δ (NdN), Pr1.97NiO4+δ (PrN), and La0.8Sr0.2MnO3 (LSM) into specific backbone cathodes: electronic conductor LSM, ionic conductor SDC and mixed ionic and electronic conductor NdN. The electrochemical performances of the symmetrical half-cells and single cells were improved using impregnated cathodes. The loading amount of the promoters have been optimized to decrease the Area Specific Resistance of the electrode (ASRelec) and improve performance of IT-SOFCs with NdN composite cathode. The electrochemical measurements showed that a MIEC backbone is more efficient than a pure electronic or a pure ionic one. The highest ASRelec was given by LSM-impregnated sample (ASRelec = 1.15 Ω.cm2) at 700 °C. At the same temperature, the lowest ASRelec was measured on a PrN impregnated into a NdN backbone (ASRelec = 0.26 Ω.cm2). Complete single SOFC with and without infiltrated air electrodes have been then manufactured and the infiltration improved clearly the efficiency of the cell, more than 6% in the temperature range 650-750°C without specific optimization.