ELECTROCHEMICAL, XAS AND FTIR STUDY OF LITHIUM INTERCALATION IN NA1+XV3O8

Slow scan rate cyclic voltammetry, X-ray absorption (XAS) and FTIR spe ctroscopy have been used to study the intercalation of lithium in Na1xV3O8 prepared using a high temperature (HT) and a low temperature (LT ) synthetic route. Ah techniques provide evidence for different struct ural evolution in the two forms as lithium is inserted. The LT form ha s been found to be able to intercalate more lithium than the HT form ( 4.5 versus 2.3 moles per unit formula). The ability of the LT form to intercalate more lithium can be related to a limited long range order that is further reduced upon lithiation. The XAS spectra reveal that, during lithium intercalation, a partial loss of long range order also occurs in the HT form. The lithium apparent diffusion coefficients in both forms have also been measured electrochemically and found to be v ery similar.