Cycling Studies of Microtubular SOFCs

Abstract

A major problem of solid oxide fuel cells (SOFCs) is their long term durability under cyclic operation, for example during start-up and shutdown, where cracking can occur. The objective of this project was to understand these mechanisms of cyclic degradation for microtubular SOFCs, then to set up experiments to measure the degradation in terms of the drop in electrochemical performance, subsequently confirming the theories by dilatometry and scanning electron microscopy (SEM). First, a theory of degradation based on micro-crack propagation due to expansion/contraction of the Ni cermet anode was propounded. Several experiments were then designed to illustrate the degradation phenomena including temperature and redox cycling.