In the present work, microstructure evolution of the Ni-yttria stabilized zirconia (YSZ) is followed as a function of galvanostatic steam electrolysis testing at current densities between -0.5 and -1.0 A cm-2 for periods of up to 750 hours at 800 °C. The volume fraction and size of the percolating Ni particles was statistically quantified using the mean linear intercept method as a function of current density and correlated to increases in serial resistance.
The above structural changes are then compared in terms of electrode degradation observed during the co-electrolysis of steam and CO2 at current densities up to -1.5 A cm-2. In this study, the formation of ZrO2 based nano particles at the Ni-pore interface is responsible for the loss of Ni-YSZ particle contact and thus loss of triple phase boundary. Formation of similar nano particles at Ni internal grain boundaries is also thought to be responsible for loss of Ni percolation.
|Publication status||Published - 2013|
|Event||Thermec 2013 - International Conference on Processing & Manufacturing of Advanced Materials: Processing, Fabrication, Properties, Application - Las Vegas, United States|
Duration: 2 Dec 2013 → 6 Dec 2013
|Conference||Thermec 2013 - International Conference on Processing & Manufacturing of Advanced Materials|
|Period||02/12/2013 → 06/12/2013|