| Popis: |
The LiMn2O4 cathodes for lithium ion battery were synthesized from various pre- cursors of manganese oxides and manganese hydroxides. As the first step, nanosized precursors such as α-MnO2 (nano-sticks), β-MnO2 (nano-rods), Mn3O4 (nano-octahedra), amorphous MnO2(nano-spheres), and Mn(OH)2 (nano-plates) were prepared by a hydrothermal or a pre- cipitation method. Spinel LiMn2O4 with various sizes and shapes were finally synthesized by a solid-state reaction method from the manganese precursors and LiOH. Nano-sized (500 nm) octahedron LiMn2O4 showed high capacities of 107 mAh g �1 and 99 mAh g �1 at 1 C- and 50 C-rate, respectively. Three dimensional octahedral crystallites exhibit superior electrochemical characteristics to the other one-dimensional and two-dimensional shaped LiMn2O4 nanoparticles. |
