Klemensø, Trine1; Appel, C. C.4; Mogensen, Mogens Bjerg3
1 Risø National Laboratory for Sustainable Energy, Technical University of Denmark2 Haldor Topsoe AS3 Department of Energy Conversion and Storage, Technical University of Denmark4 Haldor Topsoe AS
The anode-supported solid oxide fuel cell (SOFC) degrades when the anode is subjected to redox cycling. The degradation has qualitatively been related to microstructural changes in the nickel-yttria stabilized zirconia anode of the tested cells. In this work, the microstructural changes were observed in situ using environmental scanning electron microscopy. In the reduced state, a dynamic rounding of the nickel particles occurred. The oxide growth upon re-oxidation depended on the oxidation kinetics. During rapid oxidation, the NiO particles divided into 2-4 particles, which grew into the surrounding voids. For slower oxidation, an external oxide layer was seen to develop around the individual particles. (c) 2006 The Electrochemical Society.
Electrochemical and Solid-state Letters, 2006, Vol 9, Issue 9