Improved performances of mechanical-activated LiMn2O4/MWNTs cathode for aqueous rechargeable lithium batteries

LiMn2O4/multi-walled carbon nanotubes (MWNTs) composite was synthesized by mechanical activation reaction followed by a heat-treatment (500 A degrees C). The LiMn2O4 and LiMn2O4/MWNTs as cathodes were investigated in 1 M Li2SO4 by cyclic voltammetry (CV), galvanostatic charge/discharge (GC), and electrochemical impedance spectroscopy (EIS). The LiMn2O4/MWNTs cathode delivered higher discharge capacity (117 mAh g(-1)) than LiMn2O4 (84.6 mAh g(-1)). Furthermore, the results from EIS showed that LiMn2O4/MWNTs had a faster kinetic process for lithium ion intercalation/de-intercalation than LiMn2O4. Besides, LiMn2O4/MWNTs had better cycling stability and rate capability than LiMn2O4, which was confirmed by GC testing. SEM images showed that a three-dimensional network structure was formed during the mechanical activation, giving a decrease of particle size.