Structural refinement of delithiated LiVO₂ by neutron diffraction

Lithium has been extracted from the layered compound LiVO₂ by chemical oxidation with bromine. Previous X-ray data have shown that in Li_1-xVO₂ lithium extraction beyond x ˜ 0.33 is accompanied by migration of one-third of the vanadium ions into the lithium-deficient layer to stabilize the structure; little information about the location of the lithium ions could be gathered from this data. The neutron diffraction data presented in this paper show that at a composition Li_0.22VO₂, determined by atomic absorption spectroscopy, the residual lithium ions are distributed over the octahedral sites of the original lithium layer; the possibility that a small fraction of the lithium ions partially occupy the tetrahedral sites in this layer cannot be discounted. No significant occupation by lithium of the tetrahedral or octahedral vacancies in the vanadium-rich layer could be detected. © 1987.