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In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries
Published on: November 10, 2014
Crystal Structure and Lithium Diffusion Pathways of a Potential Positive Electrode Material for Lithium-Ion
Edouard Boivin1,2,3, Christian Masquelier1,3,4, Laurence Croguennec2,3,4
1Laboratoire de Réactivité et de Chimie des Solides, CNRS, UMR 7314, Université de Picardie Jules Verne , F-80039 Amiens Cedex 1, France.
Abstract:
A new potentially interesting material as a positive electrode for lithium-ion batteries, Li2VIII(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 Li2FeIII(PO4)(HPO4) and also closely related to Li2FeII(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 Li2FeIII(PO4)(HPO4) and Li2FeII(SO4)2 allows one to investigate, by comparison, the effect of the hydrogen atoms lying on lithium diffusion pathways.
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