Abstract
The purpose of this work is the search and development of new-based composite materials as negative electrode for rechargeable lithium ion batteries. In order to understand the relationship structure-texture-properties allowing to optimize this material, several complementary techniques of characterization (X-ray diffraction, scanning electron microscopy, differential scanning calorimetric and thermo gravimetric analysis, 119Sn Mössbauer spectroscopy, X-ray absorption) were coupled to study global and local order in the composite material. Accurate analysis of the lithium reaction mechanism for the composite material [Sn-BPO4], realized by coupling electrochemical and spectroscopic methods, made it possible to understand the reversibility of the system and to highlight the reactional intermediaries thanks in particular to in situ 119Sn Mössbauer spectroscopy. The composite material tested in laboratory cells shows good electrochemical performances (high specific capacity : 500 mAh.g-1 and good capacity retention) wich are associated in particular with high dispersion of electroactive particles and their fixing on the surface of the matrix. Pinning makes it possible to maintain the performances of metallic tin, while absorbing volumes change and avoiding particles coalescence. The optimized composite material was tested under industrial conditions by SAFT-Bordeaux. The aim was test the influence of industrial electrode technology on electrochemical performances.