Synergistic Effect for LiMn2O4Microcubes with Enhanced Rate Capability and Excellent Cycle Stability for Lithium Ion Batteries

Monodispersed porous LiMn 2 O 4 microcubes assembled with closely-packed nanograins and coated with Mn 2 O 3 have been prepared through a solid state reaction between LiOH and MnO 2 microcubes, the latter obtained via hydrothermal treatment. Scanning electron microscopy and transmission electron microscopy are utilized for microstructure investigation and nanograins, macropores and Mn 2 O 3 surface overlayer are clearly observed. Cyclic voltammography and galvanostatic charge-discharge technique are employed to study the electrochemical performance of LiMn 2 O 4 . The results show that the LiMn 2 O 4 microcubes have superior high rate capability, delivering an initial discharge capacity of 120 mAh g −1 at 0.1 C and 94 mAh g −1 even at a high rate of 20 C. Moreover, the cycling performance of the cathode is also outstanding. 80% of initial discharge capacity can be preserved when cycled at 10 C for 500 cycles. The improved performance suggests that the prepared LiMn 2 O 4 microcubes are highly promising for high power lithium batteries.