MECHANOCHEMICAL SYNTHESIS OF CATHODE MATERIALS FOR LITHIUM BATTERIES

摘要

Lithium transition metal oxides (Mn, Co, Ni, Ti, and V) with spinel and layered structure are of interest as cathode materials for rechargeable lithium battery application. As a rule, the synthesis of these compounds is carried out by conventional thermal treatment procedure at high temperatures. It results in the formation of poorly dispersed product with insufficient electrochemical activity. In recent years low-temperature methods are used to prepare these compounds of high homogeneity and high dispersion. Mechanochemical technique is the efficient method which allows to obtain high dispersed compounds either directly during mechanical activation at close to room temperature or by preliminary activation followed by heat treatment at relatively low temperatures. It results in obtaining final products with smaller size of particles and a highly strained lattice. In this study the results of mechanochemical synthesis of stoichiometric LiMn_2O_4 spinel and nonstoichiometric defect spinel type compounds Li_xMn_2O_4 are reported. The investigation of the influence of different factors on the process of synthesis as well as the composition, structure, transport and electrochemical properties of products is performed.