Aluminum substitution for vanadium in the Na3V2(PO4 )2F3 and Na3V2(PO4)2FO2 type materials

Jacob Olchowka (1, 2, 3) , Long H. B. Nguyen (4, 1, 2) , Thibault Broux (1, 2, 3, 4) , Paula Sanz Camacho (1, 2) , Emmanuel Petit (1, 2, 3) , François Fauth (5) , Dany Carlier (1, 2, 3) , Christian Masquelier (4, 2, 3) , Laurence Croguennec (1, 2, 3)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 RS2E - Réseau sur le stockage électrochimique de l'énergie
3 ALISTORE-ERI - Advanced Lithium Energy Storage Systems - ALISTORE-ERI
4 LRCS - Laboratoire réactivité et chimie des solides - UMR CNRS 7314
5 ALBA Synchrotron light source [Barcelone]

Among the positive electrode materials for Na-ion batteries, Na3V2(PO4)2F3 is considered as one of the most promising and generates high interest. Here, we study the influence of the sol–gel synthesis parameters on the structure and on the electrochemical signature of the partially substituted Na3V2−zAlz(PO4)2(F,O)3 materials. We demonstrate that the acidity of the starting solution influences the vanadium oxidation state of the final product. For the first time we report on the possibility of controlling the double Al/V and O/F substitution that leads to the preparation of the Na3V2−zAlz(PO4)2F1+zO2−z solid solution.

Domaines: Matériaux

Jacob Olchowka, Long H. B. Nguyen, Thibault Broux, Paula Sanz Camacho, Emmanuel Petit, et al.. Aluminum substitution for vanadium in the Na3V2(PO4 )2F3 and Na3V2(PO4)2FO2 type materials. Chemical Communications, 2019, 55 (78), pp.11719-11722. ⟨10.1039/C9CC05137F⟩. ⟨hal-02294384⟩