Surface modification of LiCo_0.05Mn_1.95O₄ cathode by coating with SiO₂-TiO₂ composite

【Abstract】 The cycling characteristics and low specific capacity of LiMn₂O₄ have always been the greatest obstacle to its commercialization. For the improvement of cyc le performance,the surface of LiCo_0.05Mn_1.95O₄ was coated with ve ry 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 （SEM）. The electrochemical performances of un coated and SiO₂-TiO₂ coated LiCo_0.05Mn_1.95O₄ spinel at 25 ℃ and 55 ℃ were studied with a voltage range of 3.04.35V and a current density of 0.1 mA/cm². There is a slight decrease in the initial discharge ca pacity of coated LiCo_0.05Mn_1.95O₄（119 mA·h/g） compared with that of uncoated （123 mA·h/g）. However the cycle ability of LiCo_0.05Mn_{1. 95}O₄ coated by SiO₂-TiO₂ is improved. It is proposed that surface treat ment is an effective method to improve the cycle performance of LiCo_0.05Mn _1.95O₄. The surface modification is successful in minimizing the harmful side reactions within the batteries by placing a protective barrier layer betwe en the oxidizing cathode material and the liquid electrolyte.更多还原