摘要
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 LiCo0.05Mn1.95O4 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 LiCo0.05Mn1.95O4 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 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 treat ment is an effective method to improve the cycle performance of LiCo0.05Mn 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.
The cycling characteristics and low specific capacity of LiMn_2O_4 have always been the greatest obstacle to its commercialization. For the improvement of cyc le performance,the surface of LiCo_(0.05)Mn_(1.95)O_4 was coated with ve ry fine SiO_2-TiO_2 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 SiO_2-TiO_2 coated LiCo_(0.05)Mn_(1.95)O_4 spinel at 25 ℃ and 55 ℃ were studied with a voltage range of 3.04.35V and a current density of 0.1 mA/cm^2. There is a slight decrease in the initial discharge ca pacity of coated LiCo_(0.05)Mn_(1.95)O_4(119 mA·h/g) compared with that of uncoated (123 mA·h/g). However the cycle ability of LiCo_(0.05)Mn_(1. 95)O_4 coated by SiO_2-TiO_2 is improved. It is proposed that surface treat ment is an effective method to improve the cycle performance of LiCo_(0.05)Mn _(1.95)O_4. 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.
出处
《中国有色金属学会会刊：英文版》
CSCD
2004年第4期723-727,共5页
Transactions of Nonferrous Metals Society of China
基金
Project(0 2JJY2 0 81)supportedbytheNaturalScienceFoundationofHunanProvince,China
