中國(guó)有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 14 No. 4 August 2004 |
coating with SiO2-TiO2composite①
XIAO jin(肖 勁)1, CHEN Zhao-yong(陳召勇)1, LIU Ye-xiang(劉業(yè)翔)1
（1. School of Metallurgical Science and Engineering,
Central South University, Changsha 410083, China;
2. School of Chemistry and Chemical Engineering,
Central South University, Changsha 410083, China）
Abstract:The cycling characteristics and low specific capacity of LiMn2O4have 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-TiO2composite 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 uncoated and SiO2-TiO2coated LiCo0.05Mn1.95O4 spinel at 25℃and 55℃were studied with a voltage range of 3.0 4.35V and a current density of 0.1 mA/cm2. There is a slight decrease in the initial discharge capacity of coated LiCo0.05Mn1.95O4 (119mA·h/g) compared with that of uncoated (123 mA·h/g). However the cycle ability of LiCo0.05Mn1.95O4coated by SiO2-TiO2is 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.
Key words: lithium-ion batteries; surface modification; SiO2-TiO2coating; LiCo0.05Mn1.95O4 cathode
