New preparation method and electrochemical property of LiMn2O4 electrode

Abstract

Several doped spinel-type Li-Mn oxides of formula LiMn2-xMxO4, where Mn is partly replaced by Co, Cu, Ga, were prepared by the Pechini method in the range of 700-850 degreesC for 4h. Even substitution levels as low as 0.1 atom/formula unit produces structural effect that resulted in high cycle performance. The cylcleability maintained regardless of synthesis temperature or powder size. It is suggested that high Mn Valence State by doping significant effect on cylcleability. Also, Spinel lithium manganese oxides with a nominal composition of LiMn2O4 are prepared by using conventional ceramic synthesis method and are coated by a chemical deposition method of Ag particles onto LiMn2O4 powder. The Ag nano-particle coated LiMn2O4 showed excellent cycleability at 2 C galvano-static condition. The results indicated that the surface treatment on cathode powder also should be an effective way to improve cyclelife and high current retention. This work aims to elucidate electrochemical properties by doping and coating. (C) 2004 Elsevier Ltd. All rights reserved.