PREPARATION AND CHARACTERIZATION OF LIMN2O4 POWDER BY COMBUSTION OF POLY(ETHYLENE GLYCOL) METAL NITRATE PRECURSOR

LiMn2O4 powders were prepared by burning and subsequent calcination of PEG-metal nitrate precursor. After the burning stage of the precursor , some minor phases such as Mn2O3 (or Mn3O4), MnO, and carbonate were formed and single phases of LiMn2O4 were obtained by further calcinati ons above 400 degrees C. From thermal analysis of the precursor, a vio lent thermal decomposition, which was indicated by a drastic weight lo ss accompanied by a sharp and strong exothermic peak, was observed and probably caused by an oxidation-reduction reaction between oxidizer a nd fuel. The formation of the minor phases could be explained in terms of the burning behavior of the precursor by employing valence concept s of propellant chemistry. The calcined powders were composed of submi cron-sized but highly agglomerated particles and showed very broad par ticle size distribution.