Preparation of stoichiometric γ″-LiV 2O 5 bronze crystals from YVO 4 doped LiVO 3 flux for investigation of γ″-γ′ phase relation

Abstract

Recently the γ lithium vanadium bronzes have been ranked as the most promising cathode materials for nonaqueous and solid state rechargeable lithium batteries. In spite of their advantageous properties, relationships between the two basic kinds of γ-Li-V bronze phases have not been investigated. Since these bronzes can easily form various oxygen and Li/V stoichiometries in the complex Li-V-O system, stoichiometric LiV 2O 5 bronze by solid state preparation techniques is difficult to achieve. From the V 2O 5-Li 2O-V 2O 3 ternary system it was also recognized that the basic relation of γ[prime]-Li 1+ x V 3O 8 and γ″-LiV 2O 5 phases is connected to their oxygen stoichiometry. Crystallized γ″-LiV 2O 5 bronze powder was prepared from a YVO 4-doped LiVO 3 solvent system. This flux crystallization technique can produce better quality stoichiometry γ″-LiV 2O 5 bronze phase (than previously reported methods) having more accurate crystallographic data, a=9.6719 A ̊ , b=3.5992 A ̊ , c=10.6591 A ̊ . During melting and subsequent solidification the incongruent melting γ″-LiV 2O 5 transforms into γ′-Li 1+ x V 3O 8+LiVO 3 phases.