Crystal structure and lithium diffusion pathways of a potential positive electrode material for lithium-ion batteries: Li2VIII(H0.5PO4)2

Edouard Boivin (1, 2, 3) , Christian Masquelier (4, 1, 2) , Laurence Croguennec (2, 3, 4) , Jean-Noël Chotard (1, 2, 4)

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

A new potentially interesting material as a positive electrode for lithium-ion batteries, Li2V(III)(H0.5PO4)2, was obtained by hydrothermal synthesis. Its crystal structure was solved thanks to single-crystal X-ray diffraction. This material is isostructural to Li2Fe(III)(PO4)(HPO4) and also closely related to Li2Fe(II)(SO4)2. It can be described as a VO6 octahedron sharing corners with six PO4 tetrahedra to form a 3D framework. One oxygen atom of each phosphate group is unshared with a vanadium octahedron and as such linked to a hydrogen atom. The arrangement of these polyhedra generates large channels running along [100] in which lithium cations are located. The close structural relationship between Li2Fe(III)(PO4)(HPO4) and Li2Fe(II)(SO4)2 allows one to investigate, by comparison, the effect of the hydrogen atoms lying on lithium diffusion pathways.

Domaines: Matériaux

Edouard Boivin, Christian Masquelier, Laurence Croguennec, Jean-Noël Chotard. Crystal structure and lithium diffusion pathways of a potential positive electrode material for lithium-ion batteries: Li2VIII(H0.5PO4)2. Inorganic Chemistry, 2017, 56 (12), pp.6776-6779. ⟨10.1021/acs.inorgchem.7b00792⟩. ⟨hal-01545848⟩