The formation and propagation of cracks in SOECs originates from an anomalous change in the oxygen chemical potential, μ_(O_2 ), at the oxygen electrode – electrolyte interface. This work offers a theoretical analysis that considers both electrochemistry and elasticity to study the effect of pertinent parameters on the electrochemically driven crack formation, crack growth kinetics, and their dependence on μ_(O_2 ) distributions. Our analysis shows that an electronic insulating and ionic conductive interface between oxygen electrode and electrolyte is in favor of suppressing crack formation and propagation in an SOEC. There exists a critical pressure inside the crack for a YSZ electrolyte, which is 5,878 atm when the diameter of a crack is 1 μm. If the cell voltage is lower than 1.44 V, our analysis shows that no crack propagation is expected under the conditions selected. Conversely, operating the cell at a higher voltage results in a higher pressurization rate, leading to the formation of cracks. The optimal operation between constant current density or constant voltage is discussed by studying the dependence of μ_(O_2 ) on materials transport properties and steam concentration. Results from this work can be used to remedy crack problems and improve performance and durability.

Excimer laser annealing provides a rapid and efficient means for surface alloying and modification of ceramic materials. In this study, Alumina-13% Titania coatings were sprayed with a water-stabilized plasma spray gun. The coated surface was treated by Excimer laser having a wavelength of 248 nm and pulse duration of 24 ns. The surface structure of the treated coating was examined by field emission scanning electron microscope and X-ray diffraction (XRD). A detailed analysis of the effects of various laser parameters including laser energy density (fluence), pulse repetition rate (PRR), and number of pulses on the morphology and the microstructure of the coatings are presented.