LiMn₂O₄ Microspheres: Synthesis, Characterization and Use As a Cathode in Lithium Ion Batteries

Solid and hollow microspheres of LiMn₂O₄ have been synthesized by lithiating MnCO₃ solid microspheres and MnO₂ hollow microspheres, respectively. The LiMn₂O₄ solid microspheres and hollow microspheres had a similar size of about 1.5 μm, and the shell thickness of the hollow microspheres was only 100 nm. When used as a cathode material in lithium ion batteries, the hollow microspheres exhibited better rate capability than the solid microspheres. However, the tap density of the LiMn₂O₄ solid microspheres (1.0 g/cm³) was about four times that of the hollow microspheres (0.27 g/cm³). The results show that controlling the particle size of LiMn₂O₄ is very important in terms of its practical application as a cathode material, and LiMn₂O₄ with moderate particle size may afford acceptable values of both rate capability and tap density.