Two-phase reaction mechanism during chemical lithium insertion into α-MoO3

Abstract

The phase transition during chemical lithium insertion into α-MoO3 was investigated by chemical analysis, X-ray diffraction (XRD) and electrochemical characterisation. The samples have been prepared by reaction of various amounts of water-free lithium iodide with fine-particulate orthorhombic molybdenum trioxide in n-hexane (non-aqueous media), which yielded materials with different Li/Mo ratio. XRD investigations of these materials proved that the crystal structure of the layered α-MoO3 has been changed after the chemical lithiation. The phase transition ranged from 0.25 < x < 0.5 in LixMoO3 upon chemical lithium insertion into α-MoO3. The XRD lines of lithium inserted phase LixMoO3 grew at the expense of the XRD lines of the pristine α-MoO3 as lithium ions were chemically inserted until the disappearance of lines related to α-MoO3. The electrochemical performance of the lithiated samples is improved in comparison with the starting material (non-lithiated α-MoO3).