8. Conclusion

Ion migration and the presence of defects are the key parameters of oxide ion conductors. To be developed for a wide range of applications (solid oxide fuel cells, high-temperature electrolyzers, membranes for the electrochemical separation of oxygen from air), improving their electrochemical performance depends on a sound understanding of their structure, intrinsic properties and oxygen transport parameters. In addition, control of material shaping can play a decisive role in performance. Controlling these different parameters is the key to optimizing materials and commercializing applications still at the R&D stage. In this context, the experimental characterization techniques presented in this article, combined with atomic modeling studies, are essential. Complementary, they provide insights into the mechanisms involved.