THE USE OF ACETATES AS PRECURSORS FOR THE LOW-TEMPERATURE SYNTHESIS OF LIMN2O4 AND LICOO2 INTERCALATION COMPOUNDS

The spinel LiMn2O4 and layered LiMO2 (M = Co, Ni) compounds, which are of potential interest for Li intercalation applications, have been synthesized at low temperatures from aqueous solutions of hydroxides, nitrate, and acetate salts. These phases can be prepared in bulk or thick-film form with their crystallization temperature being strongly dependent on oxygen pressure, annealing time, and Li/transition-metal (M) ratio. For instance, we succeeded in preparing the spinel LixMn2O4 (x = 1) at temperatures as low as 300°C, whereas a temperature of 500°C was needed to obtain the LiCoO2 phase. Rechargeable Li batteries using the LiMn2O4 powders, synthesized at low temperatures, show good capacity and good cycling behavior. Larger amounts of Li (x > 1) cannot be directly introduced into the spinel phase by heat treatment under less oxidizing atmospheres obtained by use of mixtures of argon and oxygen. © 1991.