Dr. Bowen Song, Department of Earth Science and Engineering, Imperial College London, United Kingdom.

Speech Title: The Impact of redox cycling on nickel cermet anodes for solid oxide fuel cell

Abstract: Ni-YSZ anodes for Solid Oxide Fuel Cells are vulnerable to microstructural damage during redox cycling leading to a decrease in the electrochemical performance. This study is going to present a quantification of the microstructural changes as a function of redox cycles at 800 °C and associates it to the deterioration of the mechanical properties and polarisation resistance for the classic Ni-YSZ anode. The triple phase boundaries reduction, mechanical instability, YSZ framework failure, Ni agglomeration and increase in porosity has been observed. This methodology has been applied to mechanical stability enhanced Ni infiltrated YSZ scaffold at 550°C operational temperature. The YSZ framework failure was prevented, and the degradation has been minimized. FIB-SEM was used to quantify microstructure degradation, including: Ni particles volume, surface area, distribution, triple phase boundaries and electrode porosity. Additional work has been done with in-situ Ni agglomeration coupled with electrochemical degradation on the 2D symmetrical cell. For the first time in the field to link electrochemical performance with in-situ cell morphology and physically based modelling.