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

Abstract

Li–Mn–O oxides were synthesized by mechanochemistry from a stoichiometric mixture of Li 2O and MnO 2 using various grinding times (0< t milling<15 h). X-ray diffraction patterns of the ground samples ( t milling <10 h ) exhibit the same features as LiMn 2O 4 spinel structure (SG: Fd3m) with, however, a slight discrepancy in the lattice parameter ( a cub) suggesting a non-stoichiometry of the Li–Mn–O oxides. a cub increases with milling time to reach for 8 h of grinding a value of 8.24 Å similar to stoichiometric LiMn 2O 4. As a matter of fact, after 8 h of milling, mechanosynthesized Li–Mn–O spinel-type oxide shows quasi-identical electrochemical performances as high temperature LiMn 2O 4 ground for 1 h.