Mechanochemical synthesis of Li-Mn-O spinels: positive electrode for lithium batteries

Li-Mn-O oxides were synthesized by mechanochemistry from a stoichiometric m ixture of Li2O and MnO2 using various grinding times (0 < t(milling) < 15 h ). X-ray diffraction patterns of the ground samples (t(milling) < 10h) exhi bit the same features as LiMn2O4 spinel structure (SG: Fd3m) with, however, a slight discrepancy in the lattice parameter (a(cub)) suggesting a non-st oichiometry of the Li-Mn-O oxides. a(cub) increases with milling time to re ach for 8 h of grinding a value of 8.24 Angstrom similar to stoichiometric LiMn2O4. As a matter of fact, after 8 h of milling, mechanosynthesized Li-M n-O spinel-type oxide shows quasi-identical electrochemical performances as high temperature LiMn2O4 ground for 1 h. (C) 2001 Elsevier Science B.V. Al l rights reserved.