ELECTROCHEMICAL STUDY OF THE PASSIVATING LAYER ON LITHIUM INTERCALATED CARBON ELECTRODES IN NONAQUEOUS SOLVENTS

Carbonaceous materials are now actively investigated as alternative an odes in lithium rechargeable cells. However, practical problems arise from the electrolyte reactivity at low potential, such as low cycling efficiency during the first charge and high self-discharge rate. The p assivation of the carbon is mainly responsible for this initial lack o f reversibility, and it was mainly followed by electrochemical methods on carbon tissues that constitute all carbon electrodes of sufficient mechanical stability. The amount of charge necessary to passivate the electrode could be minimized with appropriate choice of electrolyte. Solubilization of the passivating layer in the electrolyte appeared to be the main mechanism of self-discharge and some additives were found efficient for charge retention.