Capacity fading of LiMn2O4 electrode: Influence of calcination temperature

Abstract

Spinel-type Li-Mn oxides of formula LiMn2-xO4 were prepared by the Pechini method in the range of 600-850degreesC for 4 h. These spinels were investigated by X-ray powder diffraction, SEM (scanning electron microscope), ICP, chemical titration and galvanostatic cycling at 0.2C rates. The effect of calcination temperature is evaluated. With increasing calcination temperature, Mn valence-state of the powder decreased while size of powder increased. The cycle life of the powder decreases with increasing calcination temperature. The results indicated that the Mn valence-state and powder size of cathode powder should be important variables to improve cycle life. The effect of cell polarization effect on the cycle life is also discussed. (C) 2004 Kluwer Academic Publishers.