Proprietà di trasporto elettrico del tiofosfato di ferro intercalato con il litio

Abstract

We have carried out $dc$ conductivity measurements on the lithium intercalation complexes $Li_xFePS_3$ both during the intercalation process and after the intercalation was ceased. Prelirninary results for equilibrated samples are presented as a function of both the temperature and the intercalation time. As in the $Li_xNiPS_3$ case, an increase in the electrical conductivity and a contemporary decrease in the activation energy are observed, These features seem to indicate that, with respect to the pure $FePS_3$, a new conduction mechanism takes piace at a different energy levei since the very beginning of the intercaiation process. In the eariy intercalation times, the empirical model, proposed for the $Li_xNiPS_3$ complexes, was used to correlate the data as a function of the intercalation time and as a function of temperature. For the investigated intercalation times a possibie nature of the reduction sites is also provided