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 ?m, 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.