The mechanisms of electrochemical reactivity of Li+ towards oxides and sulfides are numerous and have been reviewed in this lecture. The chemistry and physics of intercalation reactions were first presented. These are reactions by which a host structure (MX2) accommodates an alkali cation (Li+, Na+, Mg2+) without altering the structural framework, i.e. without breaking bonds. The importance of the material's crystallographic structure, including the number of Li+ sites and their coordination (tetrahedral, octahedral, prismatic), as well as its electronic structure (e.g. band structure) on the electrochemical capacity of the material and its potential with respect to Li+ were detailed, as were the thermodynamic and kinetic aspects of these reactions. All these considerations were illustrated by specific, topical examples. With this in mind, the electrochemical activity of the host structure's recently-discovered anionic network was presented, thus putting an end to twenty-five years of well-established dogma which stipulated that insertion phenomena were only associated with a cationic redox reaction.
16:30 - 17:30
Lecture
The richness of Li electrochemistry in terms of reaction mechanisms (insertion, alloying, conversion and displacement reactions)
Jean-Marie Tarascon
16:30 - 17:30
