Improved Electrochemical Performance of LiMn2O4/Graphene Composite as Cathode Material for Lithium Ion Battery

Abstract

The electrochemical performance especially rate capability of LiMn2O4 is improved by graphene modified via ultrasonic agitation. The pristine LiMn2O4 and LiMn2O4/graphene composite are characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The obtained LiMn2O4/graphene composite shows reversible capacity of 107 mAh g-1 at 50 C charge/discharge rate. At 55 °C, the capacity at 5 C charge/discharge rate for LiMn2O4/graphene is higher than that of pristine LiMn2O4. The electrochemical impedance spectroscopy (EIS) indicates that the charge transfer resistance for LiMn2O4/graphene composite is reduced compared to LiMn2O4 sample.