Two types of layered compounds, Li0.96VO2 and Li0.86V0.8O2 (R (3) over barm), were synthesized with a solid-state and a hydrothermal reaction, respectively, and their structural modifications caused by electrochemical lithium extraction were investigated. The Li0.96VO2 and Li0.86V0.8O2 compounds are characterized by the ordered and disordered arrangement of vanadium ions in the alternate layers of octahedral 3a (0 0 0) and 3b (0 0 1/2) sites, respectively. According to the electrochemical lithium extraction, the Li0.96VO2 changed to a disordered arrangement; such a structural modification is irreversible and takes place in the initial stage of the lithium extraction. For the Li0.86V0.8O2, no significant structural modification was detected. (c) 2007 Elsevier B.V. All rights reserved.