Morphology-controlled synthesis of RGO/LiMn2O4 nanocomposite as cathodic Li-ion battery materials and its lithium insertion/extraction study

摘要

In the present work, beta- MnO2 with the morphology of stacked nanowire-decorated nanorods and gamma- MnO2 with morphology of nanosheets have been prepared by a simple and new one-step hydrothermal method without the application of any surfactants or templates. Then, the MnO2 nanostructures converted to the LiMn2O4 (LMO) with solid-state reaction. RGO and LMO/RGO nanocomposites were successfully synthesized and characterized using FT-IR, XRD, EDS, and SEM methods. The lithiation/delithiation electrochemical behaviors of nanocomposites were investigated employing electrochemical galvanostatic charge-discharge and electrochemical impedance spectroscopy. The nanorod-decorated LMO composite delivered the highest discharge capacitance of 141 mAh g(-1) at 700 mA g(-1) current density, with the capacity retention as high as 92% observed after 50 cycles.