LiMn_(1.8)Co_(0.2)O_(3.95)F_(0.05)的络合燃烧法合成及其性质研究  

Characterization of LiMn_(1.8)Co_(0.2)O_(3.95)F_(0.05) Prepared by the Combustion-assisted Soft Route

作　　者：肖卓炳[1] 麻明友[1] 刘建本[1] 

机构地区：[1]吉首大学化学化工学院,湖南吉首416000

出　　处：《中国锰业》2005年第4期14-17,共4页China Manganese Industry

基　　金：湖南省自然科学基金(编号:03JJY6005);湖南省教育厅项目(编号:02C308)

摘　　要：以醋酸锂、醋酸锰、醋酸钴、氟化锂、柠檬酸及乙二醇为原料,采用燃烧辅助有机酸络合法合成LiMn1.8Co0.2O3.95F0.05,用X射线衍射检测和分析产物的物相及晶格常数,用循环伏安、交流阻抗技术研究产物的氧化-还原及界面过程,用恒流充放电测试产物的容量及循环性能。研究表明,各条件下合成的LiMn1.8Co0.2O3.95F0.05粉末的X射线衍射峰强度大、峰尖锐,粉末具有良好的结晶性。LiMn1.8Co0.2O3.95F0.05容量随热处理温度的升高而增大,即由750℃热处理4 h的92 mAh/g升高到850℃热处理4 h的105mAh/g。相对LiMn2O4而言,LiMn1.8Co0.2O3.95F0.05的初始容量虽略有下降,但双掺杂后的循环性能得到了显著提高。LiMn1.8Co0.2O3.95F0.05 powder was prepared by the combustion-assisted soft route. The phase identi-fication and lattice parameter were studied by X-ray diffraction. The electrochemical properties of LiMn1.8Co0.2O3.95F0.05 were carried out by cyclic voltammetry, A.C. impedance, and galvanostatic charge-discharge experi-ments. The powders prepared under different conditions are of good crystallinity. The discharge capacity of LiMn1.8Co0.2O3.95F0.05 powder increases from 92 mAh/g to 105 mAh/g as the calcination temperature increasesfrom 750℃ to 850℃. The capacity loss per cycle after being cycled 20 times 0.29%, 0.15%, 0.24% respectively for LiMn1.8Co0.2O3.95F0.05 heated at 750℃, 800℃, 850℃ for 4 hours, which indicates that the multiple substitution of Co and F for Mn and O results in good cycling behavior.

关 键 词：锰酸锂 掺杂 锂离子 电化学 

分 类 号：TM912.9[电气工程—电力电子与电力传动]