Template-Synthesized LiCoO2, LiMn2O4, and LiNi0.8Co0.2O2 Nanotubes as the Cathode Materials of Lithium Ion Batteries

Abstract
The first point of this work is to synthesize LiCoO2, LiNi0.8Co0.2O2, and LiMn2O4 nanotubes with the template of porous anodic aluminum oxide by thermal decomposition of sol−gel precursors. The as-synthesized materials were open-ended nanotubes with uniform shape and size based on the analysis of scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. An “in situ reaction from nanoparticle to nanotube” mechanism was discussed for the formation process of the nanotubes. The second point of this paper is to investigate the electrochemical properties of the as-synthesized nanotubes for the cathode materials of lithium ion batteries. It was found that the nanotube electrodes exhibited better reversibility and higher discharge capacities than that of their nanocrystalline counterparts. The reason for the improved electrochemical performance of the nanotube electrodes was also interpreted.