Modification of Li[Li0.2Mn0.54Ni0.13Co0.13]O2 cathode with α-MoO3 via a simple wet chemical coating process

Abstract

α-MoO3 coated Li[Li0.2Mn0.54Ni0.13Co0.13]O2 electrode materials were obtained via a simple and effective wet chemical method. The results of X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM) and X-ray photoelectron spectroscopy (XPS) indicated that α-MoO3 had been successfully coated on the surface of pristine materials. Charge-discharge measurements demonstrated that the α-MoO3 thin layer could enhance the electrochemical performances. The initial coulombic efficiency improved from 75.7% to 89.6%, and the modified sample exhibited good cyclic performance of 87.0% at 100 mA g−1 after 100 cycles and 85.3% at 200 mA g−1 after 100 cycles with the excellent discharge properties. According to the analysis of electrochemical impedance spectroscopy (EIS) and cyclic voltammogram (CV), the largely enhanced electrochemical performance are mainly due to the restrain of the side reactions between electrode and electrolyte and the increased migration rate of Li+ between the electrode/electrolyte interface by α-MoO3 film.