This review article presents the research carried out on the electrochemical lithiation of lead and iron oxides as well as of new quaternary layered chalcogenides. The materials have been investigated not only in view of their application in ambient temperature aprotic solvent lithium cells but also to elucidate the mechanism of the fundamental process occurring during lithium discharge. For this purpose, besides electrochemical measurements, chemical, morphological, strucutural and magnetostructural analyses of the original and discharged material have been undertaken according to several techniques, such as X-ray determination, X-ray photon and Mossbauer spectroscopy. The general and particular problems and complications arising in this type of research are critically outlined. The obtained results are discussed in the frame of the more recent views and the future developments in the field, also evidencing the points deserving further attention and still under investigation.