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

Slow scan rate cyclic voltammetry, X-ray absorption (XAS) and FTIR spectroscopy have been used to study the intercalation of lithium in Na1+xV3O8 prepared using a high temperature (HT) and a low temperature (LT) synthetic route. Ah techniques provide evidence for different structural evolution in the two forms as lithium is inserted. The LT form has 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 very similar.