High performance electrodes for reduced temperature solid oxide fuel cellswith doped lanthanum gallate electrolyte I. Ni-SDC cermet anode

A Ni-samaria-doped ceria (SD(7) cermet was selected as the anode material f or reduced temperature (800 degrees C) solid oxide fuel cells. The NiO-SDC composite powder, synthesized by spray pyrolysis, was employed as the start ing anode powder in this study. The influence of Ni content in Ni-SDC cerme ts on the electrode performance was investigated in order to create the mos t suitable microstructures. It was found that anodic polarization was stron gly influenced by the Ni content in Ni-SDC cermets. The best results were o btained for anode cermets with Ni content of around SO vol.%; anodic polari zation was about 30 mV at a current density of 300 mA/cm(2). This high perf ormance seems to be attributable to the microstructure, in which Ni grains form a skeleton with well-connected SDC grains finely distributed over the Ni grains surfaces; such microstructure was also conducive to high stabilit y of the anode. (C) 2000 Elsevier Science S.A. All rights reserved.