Surface modification of LiCo0.05Mn1.95O4 cathode by coating with SiO2-TiO2 composite

The cycling characteristics and low specific capacity of LiMn2O4 have always been the greatest obstacle to its commercialization. For the improvement of cycle performance, the surface of LiCo0.05Mn1.95O4 was coated with very fine SiO2-TiO2 composite prepared by sol-gel method. The structure and morphology of the coating materials were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEW The electrochemical performances of uncoated and SiO2-TiO2 coated LiCo0.05Mn1.95O4 spinel at 25 degreesC and 55 degreesC were studied with a voltage range of 3.0 - 4.35V and a current density of 0.1 mA/cm(2). There is a slight decrease in the initial discharge capacity of coated LiCo0.05Mn1.95O4(119 mA . h/g) compared with that of uncoated (123 mA . h/g). However the cycle ability of LiCo0.05Mn1.95O4 coated by SiO2-TiO2 is improved. It is proposed that surface treatment is an effective method to improve the cycle performance of LiCo0.05Mn1.95O4. The surface modification is successful in minimizing the harmful side reactions within the batteries by placing a protective barrier layer between the oxidizing cathode material and the liquid electrolyte.