Anionic redox chemistry in Na-rich Na2Ru1−ySnyO3 positive electrode material for Na-ion batteries

Patrick Rozier (1, 2) , Mariyappan Sathiya (3, 2) , Alagar-Raj Paulraj (1) , Dominique Foix (4, 2) , Thomas Desaunay (1, 2) , Pierre-Louis Taberna (1, 2) , Patrice Simon (1, 2) , Jean‐marie Tarascon (3, 2)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 RS2E - Réseau sur le stockage électrochimique de l'énergie
3 Collège de France - Chaire Chimie du solide et énergie
4 IPREM - Institut pluridisciplinaire de recherche sur l'environnement et les matériaux

The synthesis and Na- electrochemical activity of Na-rich layered Na2Ru1−ySnyO3 compounds is reported. Like their Li-analogue, Na2Ru1−ySnyO3 shows capacities that exceed theoretical capacity calculated from the cationic redox species. The high capacity was found, by means of XPS analysis, to be associated to the accumulation of both cationic (Ru4+/Ru5+) and anionic (O2−/O2n−) redox processes. The structural evolutions during cycling have been followed and found to be associated with the cation disordering and loss of crystallinity on cycling.

Mots clés: Na-ion batteries; Cathode materials; Na-rich phases; Anionic redox activity

Domaines: Matériaux; Science des matériaux [cond-mat.mtrl-sci]; Matériaux

Patrick Rozier, Mariyappan Sathiya, Alagar-Raj Paulraj, Dominique Foix, Thomas Desaunay, et al.. Anionic redox chemistry in Na-rich Na2Ru1−ySnyO3 positive electrode material for Na-ion batteries. Electrochemistry Communications, 2015, vol. 53, pp. 29-32. ⟨10.1016/j.elecom.2015.02.001⟩. ⟨hal-01419538⟩