Operational Inhomogeneities in La_0.9Sr_0.1Ga_0.8Mg_0.2O_3–δ Electrolytes and La_0.8Sr_0.2Cr_0.82Ru_0.18O_3–δ–Ce_0.9Gd_0.1O_2–δ Composite Anodes for Solid Oxide Fuel Cells

Abstract

The electrolyte/anode interface in solid oxide fuel cells with La0.9Sr0.1Ga0.8Mg0.2O3–δ electrolytes and composite anodes containing La0.8Sr0.2Cr0.82Ru0.18O3–δ and Ce0.9Gd0.1O2–δ (GDC) was studied using transmission electron microscope Z‐contrast imaging and energy dispersive X‐ray spectroscopy. The anode/electrolyte interface of an operated cell had numerous defective regions in the electrolyte, immediately adjacent to anode GDC particles. These areas had a different chemical composition than other electrolyte regions and were crystallographically inhomogeneous. These regions were not observed in a cell reduced in hydrogen that was not operated, suggesting that they were the result of combined electrical and chemical potential gradients present during cell operation. Ru nanoparticles were observed on the chromite surfaces of the operated.