Microstructural Change of Ni–GDC Cermet Anode in the Electrolyte‐supported Disk‐type SOFC upon Daily Start‐up and Shout‐down Operations

Abstract

AbstractThe daily start‐up and shut‐down operations were carried out for the 1 kW‐class solid oxide fuel cell stack composed of 46 electrolyte‐supported disk‐type planar cells made by Mitsubishi Materials Corporation and Kansai Electric Power Company. The representative Ni–gadolinia doped ceria cermet anodes in the deteriorated cells were analyzed by the dual‐beam focused ion beam‐scanning electron microscope. The anode microstructures were reconstructed and the microstructural parameters such as triple phase boundary (TPB) length were quantified. The surface area of nickel phase decreased with an increase in the deterioration rate, leading to a reduction in the TPB length. Furthermore, the TPB length had a strong correlation with the voltage deterioration rate.