Résumé
The thesis work, presented in this manuscript, is devoted to the study of two new electrodes family used as negative electrode in Li-ion batteries : the antimonides transition metals Fe1-xNixSb2 (x= 0 ; 0.5 ; 1) and an titanium oxide named ramsdellite (Li2Ti3O7) which has a modification of the chemical formulation.The aim of this study is to identify and understand the electrochemical mechanism during the cycling of the battery. Both properties of these two family are very different, that‘s why the electrochemical behavior and also the field of application are totally different too.Several experimental and complementary techniques (X-Ray Diffraction; Mössbauer Spectroscopy, …) have been used in order to describe the starting materials and the phases obtained during the cycling. Electrochemical mechanisms obtained during the cycling are divided in two groups; first one the “insertion” mechanisms (solid solution inside ramsdellite materials), biphased type that formed intermediate phase (reaction spinel ↔ NaCl) never described in the literature (LixNiSb2, or Li4Fe0.5Sb2), the second one the “conversion” type (LixNiSb2 --> 2Li3Sb + Ni°). Reversibility, kinetic and stability of the intermediate phase are primary to control the performance of the battery.