Abstract: Mixed ionic-electronic conductors (MIEC) such as rare-earth nickelates with a general formula Ln 2 NiO 4+δ (Ln=La, Pr, Nd) appear as potential cathodes for energy production and storage systems: fuel cells, electrolysers and CO 2 converters. Since a good electrode material should exhibit important stability in operating conditions, the structural and chemical stability of different nickelate-based, well-densified ceramics have been studied using various techniques: TGA, dilatometry, XRD, Raman scattering and IR spectroscopy...