Controllable Synthesis of Co-Doped Spinel LiMn2O4 Nanotubes as Cathodes for Li-Ion Batteries

Spinel Co-LiMn2O4 nanotubes have been synthesized via solid state reaction using alpha-MnO2 nanotubes as self-templates. The as-prepared powders were investigated by XRD, TEM, and galvanostatic discharge/charge analysis. The optimal doping amount was confirmed by galvanostatic charge/discharge measurements. The results indicate that about 67% of initial capacity (115 mAh/g) of LiMn2O4 nanotubes can be retained after 50 cycles. For Co-LiMn2O4 nanotubes, the initial reversible capacity is 126.6 mAh/g and 100 mAh/g can be maintained after 50 cycles. The capacitance retention rate of Co-LiMn2O4 nanotubes is as high as 79%. These results indicate that the doping Co can effectively improve circle stability and electrochemical performance of LiMn2O4 nanotubes.