Spherical Spinel LiMn_2O_4 Preparation and Its Electrochemical Performance Improvement

The high-density spherical precursor MnCO3 was prepared by controlling the reaction conditions. Furthermore, the spinel LiMn2O4 was obtained from the precursor, which was obtained by pre-heat treatment. The product spinel LiMn2O4 has high density of more than 1.8g·cm-3 and high electrochemical activity with initial discharge capacity of 125mAh·g-1. The body-doped spinel LiMnO can be obtained by preparing doped precursor MnCO3 and the surface-doped spinel LiMnO can be obtained by coating Mn2O3. Both of the methods can improve the cycling performance and high temperature performance obviously with initial discharge capacity little lowering. Compared with body-doping, surface-doping can restrain the capacity fading more effectively. It still preserves 109mAh/g after 100 cycles at room temperature, the capacity retention is 92.4%. At high temperature of 55℃, it has 95mAh/g after 50 cycles and capacity retention of 82.6%.