Synthesis and characterization of spinel LiMn2O4 for lithium secondary battery

The preparation and characterization of spinel LiMn2O4 have been studied. S pinel lithium manganese oxides are prepared by a sol-gel method using LiNO3 and Mn(CH3COO)(2) . 4H(2)O as starting materials in which the obtained gel is heated at various temperatures after pretreatment at 350 degrees C or w ithout pretreatment in air. The LiMn2O4 samples prepared with pretreatment have uniform microsized particles while those obtained without pretreatment have agglomerated particles of irregular shapes. The thermal pretreatment at 350 degrees C improves the electrochemical behaviour in terms of dischar ge capacity and rate capability. The results can be correlated with an incr ease in lithium surface reaction sites in these materials, as inferred by t his small grain size and large surface area. (C) 2000 Elsevier Science S.A. All rights reserved.