A staggering development over the last few years within the field of electrode materials, whatever battery technology considered, has been the use of mechanochemistry to optimize materials’ electroactivity. This low temperature physical synthesis technique, which does not require solvent, is critical not only to control powder morphology, crystallinity and state of division, but also to enable the stabilization of metastable phases that cannot be achieved at high temperature. Another positive attribute of ball milling has been its use as both surface-treatment and coating techniques to control particle surfaces, and therefore to trigger materials’ electrochemical activity. To cite this article: J.-M. Tarascon et al., C. R. Chimie 8 (2005).