Electrode activation of anode-supported SOFCs with LSM- or LSCF-type cathodes

Electrode activation of SOFCs refers to one or more processes, which generally occurs during a first period of usually not longer than 100 h of applying a constant electrical load, and is associated with a decrease of the area specific resistance. To study this effect in relation to different starting-up and test conditions in more detail, the electrochemical performance between 650 and 900 degrees C of two types of anode-supported single cells, one with an La(0.65)Sr(0.3)NnO(3) (LSM) and the other with an La(0.58)Sr(0.40)Co(0.2)Fe(0.8)O(3-delta) (LSCF) cathode, was evaluated. Both types of cells, when heated to and reduced at 800 degrees C, showed a decrease of the area specific resistance during the first 70 h at 800 degrees C of exposure under constant electrical load. The initial area specific resistance of cells heated to and reduced at 900 degrees C was comparable with that of the cells reduced at 800 degrees C and exposed for 70 It at 800 degrees C under constant electrical load. In other words, electrode activation is much faster at 900 degrees C than at 800 degrees C. (c) 2006 Elsevier B.V. All rights reserved.