Recent Developments in Mechanochemical Synthesis of Cathode Materials for Rechargeable Lithium Batteries

摘要

Mechanical activation in highly energetic planetary mills is used to prepare 3 V (Li_(1+x)V_3O_8), 4 V (LiCoO_2 and LiMn_2O_4) and 5 V (substituted LiMn_2O_4) cathode materials for rechargeable lithium batteries. It is shown that Li_(1+x)V_3O_8 and LiMn_2O_4 can be prepared by direct mechanochemical synthesis while the others by subsequent brief heat treatment of activated mixtures at moderate temperatures. In many cases the use of hydroxides as initial reagents is preferable ('soft mechanochemical synthesis'). The advantages of mechanical activation for preparation of multicomponent cathode materials (doped LiCoO_2 and LiMn_2O_4) are demonstrated. The as-prepared materials are characterized by high dispersion and structural disordering providing higher discharge rates and better stability under cycling. The mechanochemical method ensures the decrease of production time and energy expenses, simplification of the process and, as a result, lower material cost, thus being more energy-efficient and ecologically clean as compared with conventional technologies.