Capacity fading of LiMn2O4 electrode: Influence of calcination temperature

Spinel-type Li-Mn oxides of formula LiMn_2–xO₄ were prepared by the Pechini method in the range of 600–850°C 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.