Coupled X-ray diffraction and electrochemical studies of the mixed Ti/V-containing NASICON: Na2TiV(PO4)(3)

F. Lalere (1, 2) , V. Seznec (1) , M. Courty (1) , J. N. Chotard (1) , C. Masquelier (1)

1 LRCS - Laboratoire réactivité et chimie des solides - UMR CNRS 7314
2 RS2E - Réseau sur le stockage électrochimique de l'énergie

The solid state synthesis of NaTiV(PO4)(3) and Na3TiV(PO4)(3) is reported. Soft chemical oxidation of the latter composition led to NASICON Na2TiV(PO4)(3) with intermediate unit cell parameters (s.g.: R (3) over barc, a = 8.610(3) angstrom, c = 21.755(6) angstrom) when compared to NaTiV(PO4)(3) and Na3TiV(PO4)(3). Coupled structural/electrochemical studies were carried out on Na2TiV(PO4)(3) for oxidation and reduction by operando X-ray diffraction. While the oxidation mechanism towards NaTiV(PO4)(3) is quite simple, the reduction mechanisms involve several mono-and bi-phasic mechanisms leading to Na3TiV(PO4)(3) as an intermediate composition and to Na4TiV(PO4)(3) eventually.

Domaines: Matériaux

F. Lalere, V. Seznec, M. Courty, J. N. Chotard, C. Masquelier. Coupled X-ray diffraction and electrochemical studies of the mixed Ti/V-containing NASICON: Na2TiV(PO4)(3). Journal of Materials Chemistry A, 2018, 6 (15), pp.6654-6659. ⟨10.1039/c7ta10689k⟩. ⟨hal-03611097⟩