Reinvestigation of trilithium divanadium(III) tris(orthophosphate), Li₃V₂(PO₄)₃, based on single-crystal X-ray data

Abstract

The structure of Li3V2(PO4)3 has been reinvestigated from single-crystal X-ray data. Although the results of the previous studies (all based on powder diffraction data) are comparable with our redetermination, all atoms were refined with anisotropic displacement parameters in the current study, and the resulting bond lengths are more accurate than those determined from powder diffraction data. The title compound adopts the Li3Fe2(PO4)3 structure type. The structure is composed of VO6 octa­hedra and PO4 tetra­hedra by sharing O atoms to form the three-dimensional anionic framework ∞ 3[V2(PO4)3]3−. The positions of the Li+ ions in the empty channels can vary depending on the synthetic conditions. Bond-valence-sum calculations showed structures that are similar to the results of the present study seem to be more stable compared with others. The classical charge balance of the title compound can be represented as [Li+]3[V3+]2[P5+]3[O2−]12.

The monoclinic form of trilithium dichromium(III) tris(orthophosphate)

“…It has been reported that the positions of Li + ions in Li 3 V 2 (PO 4 ) 3 can vary depending on the synthetic conditions while those of the V, P, and O atoms comprising the rigid framework remain intact (Yang et al, 2010). The positions of the Li1, Li3, and Li4 sites in this work are very close to those of the ordered Li sites found in Li 3 V 2 (PO 4 ) 3 (Kee & Yun, 2013).…”

“…The anionic framework of Li 3 Cr 2 (PO 4 ) 3 is the same as that of the previously reported monoclinic Li 3 V 2 (PO 4 ) 3 structure (Kee & Yun, 2013). The general structural features of this phase have been discussed previously (Patoux et al, 2003;Fu et al, 2010).…”

“…The structures of the orthorhombic form of Li 3 Cr 2 (PO 4 ) 3 have been investigated by Genkina et al (1991). Structural studies of Li 3 V 2 (PO 4 ) 3 based on single-crystal data have been reported previously by Kee & Yun (2013). The general structural features of the monoclinic phases have been discussed by Patoux et al (2003); Fu et al (2010); Yang et al (2010).…”

Vanadium phosphate as a promising high-voltage magnesium ion (de)-intercalation cathode host

“…The lattice parameters of the as-prepared C-LVP (a ¼ 8.6080(2) A; b ¼ 8.5939(2) A; c ¼ 14.7263(4) A; b ¼ 125.180(1) ) are much closer to that reported for LVP. 26 The atomic parameters are listed in Table S2 in the ESI. † Isostructural to the monoclinic structure of Li 3 Fe 2 (PO 4 ) 3 (P2 1 /c space group), LVP entails VO 6 octahedrons and PO 4 tetrahedrons, which share their apical O atoms to form a 3D framework.…”

“…The positions of the Li + ions in the empty channels (voids) vary depending on the synthetic conditions. 26 The as-prepared C-LVP composite electrodes were electrochemically delithiated using both two-electrode Li cells and three-electrode Mg cells. The electrochemical measurements were performed at 55 C, in order to fully delithiate the three Li + from LVP.…”