Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 17 No. 6 December 2007|
（1. School of Chemical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, China; 2. Insitute of Nuclear and New Energy Technology, Tsinghua University, Beijing100084, China ）
Abstract: SrF2-coated LiMn2O4 powders with excellent electrochemical performance were synthesized. The electrochemical performance of SrF2-coated LiMn2O4 electrodes was studied as function of the level of SrF2 coating. With increasing the amount of the coated-SrF2 to 2.0% (molar fraction), the discharge capacity of LiMn2O4 decreases slightly, but the cycleability of LiMn2O4 at elevated temperature is improved obviously. In view of discharge capacity and cycleability, the 2.0% (molar fraction) coated sample shows optimum cathodic behaviors. When being cycled at 55 ℃, as-prepared LiMn2O4 remains only 79% of its initial capacity after 20 cycles, whereas the 2.0% (molar fraction) coated sample shows initial discharge capacity of 108 mA∙h/g, and 97% initial capacity retention.
Key words: lithium ion batteries; LiMn2O4; surface coating; SrF2