Synthesis and electrochemistry of new layered (1 - x)LiVO₂·xLi₂TiO₃ (0 ≤ x ≤ 0.6) electrode materials

Novel electrode materials with nominal compositions of (1 - x)LiVO₂·xLi₂TiO₃ (0 ≤ x ≤ 0.6) were synthesized by carbothermal reduction reaction. All the materials were identified to have a layered structure and can be considered as a solid solution related to LiVO₂-Li₂TiO₃ system, in which Li layers was alternately stacked with the layers made of mixture of Li, V, and Ti in a ccp array of oxygen. The redox reaction associated with vanadium ions was not reversible in LiVO₂; however, introduction of the redox couple into Li₂TiO₃ made it much more reversible. A reversible capacity of about 120 mAh g^-1 remained after 90 cycles for the samples with x = 0.5 and 0.6, when they were cycled in the voltage range of 1.0-4.8 V.