A critical investigation of the effect of silver migration at the silver | alumina scandia doped zirconia electrolyte interface in solid oxide fuel cell conditions.

In this work, a critical evaluation of silver ion migration at the surface of Al 0.04 Sc 0.06 Zr 0.9 O 1.95 (AlScZrO) electrolyte is explored in intermediate temperature solid oxide fuel cells (IT-SOFCs). The behaviour of silver is systematically studied at the operating conditions of silver as a cathode, anode, or sealant in IT-SOFCs. The results to those obtained at the surface of other electrolytes (gadolinia doped ceria, samaria doped ceria and yttria-stabilized zirconia) are also analysed. In the case of cathodic polarization, a thick silver deposit is formed around the electrode on the surface of the electrolyte, which may lead to the short-circuiting of the electrodes. While for the anodic polarization, oxygen bubbles are formed between the electrode and electrolyte, leading the delamination of electrode. Silver can also migrate from unpolarized parts of the cell such as sealants. Therefore, Issues related to the application of silver in IT-SOFCs should be concerned by the scientific community. [Display omitted] • Dense AlScZrO electrolyte with high ionic conductivity developed using the Pechini method. • Assessment of silver ion migration in AlScZrO electrolyte at IT-SOFCs. • Ag migration issues leading to electrode delamination and short-circuit risks, hindering its viability in SOFCs. • Ag due to migration-induced electrode instability, discouraging its use as an electrode material or sealant. [ABSTRACT FROM AUTHOR]