Electrochemical Characteristics of the Magnesium Titanium Composite Oxide-Coated Spinel-Type Lithium Manganese Oxide

Abstract

In this experiment, the spinel-type lithium manganese oxide (LiMn 2 O 4 ) prepared via solid-phase sintering method was coated with magnesium titanium composite oxide (MgTiO x ) in the presence of polyvinyl pyrrolidone (PVP) under the ultrasonic wave. The crystal structures, surface morphologies and electrochemical properties of the sample prepared were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical analysis. The X-ray diffractions indicated that the LiMn 2 O 4 coated with MgTiO x were similar to that of the pure LiMn 2 O 4, and they both showed sharp and high peaks. The particles of the samples prepared with PVP did not aggregate obviously, and the samples were coated completely and homogeneously. At charge-discharge rates of 0.2C, the first discharge capacity can reach more than 120 mAh / g. Compared with pure LiMn 2 O 4 , the capacity attenuation of MgTiO x -coated LiMn 2 O 4 reduced after fifty cycles, and showed good electrochemical performance.