Performance Evolution of Ni-YSZ Anode-Supported SOFCs During Initial-Stage Operation

Abstract

Performance evolution of typical Ni-YSZ anode-supported SOFCs during the initial-stage operation (<100 h) under different electrical currents is systematically evaluated. It is found that the performance evolution can be roughly divided into two stages, namely activation stage (about 0-20 h) and aging stage (> 20 h), regardless of the operating current. In the activation stage, the cell performance maintains stable or slightly increases due to the enhanced anode gas-phase diffusion. While in the subsequent aging stage, the cell performance decreases significantly and gradually approaches a plateau in about 100 hours, mainly due to the weakened anode charge transfer reaction and ionic transport processes. Therefore, it is suggested that more efforts should be focused on improving the stability of anode microstructure, especially the stability of anode functional layer.