High-performance Ni-SDC cermet anode for solid oxide fuel cells at medium operating temperature

A samaria-doped ceria (SDC)-NiO composite powder produced by spray pyrolysi s (SP) was employed as the anode material for medium-temperature (800 degre es C) solid oxide fuel cells (SOFC). Ni-SDC cermet electrodes were prepared with the expectation that their mixed conducting nature would enhance the electrode reaction rate and improve the operation efficiency of the SOFC. I n this study, different microstructures were obtained by varying the sinter ing temperature from 1200 to 1400 degrees C. The anodic polarization was st rongly influenced by the microstructure of the anode. The lowest anode pola rization of the samples sintered at 1300 degrees C for a current density of 200 mA/cm(2) was about 30 mV. This high performance seems to be due to the microstructure, in which Ni particles form a skeleton with well-connected SDC particles finely distributed over the Ni particle surfaces. (C) 1998 Th e Electrochemical Society. S1099-0062(98)05-031-7. All rights reserved.