镁离子掺杂对Li_4Ti_5O_(12)/C结构和电化学性能的影响  

Effects of Mg ion doping on structure and electrochemical performance of Li_4Ti_5O_(12)/C

作　　者：尹艳红[1,2] 范志娟[1,2] 闫林林[1,2] 谷继峰[1,2] 杨书廷[1,2] 

机构地区：[1]河南师范大学化学与环境科学学院,河南新乡453007 [2]河南省动力电源及关键材料工程技术研究中心,河南新乡453007

出　　处：《电源技术》2010年第8期793-796,共4页Chinese Journal of Power Sources

基　　金：河南省重点科技攻关项目(072102230008)

摘　　要：以乳酸镁为Mg2+的掺杂源和部分碳源,以乙醇为溶剂,在惰性气氛下采用高温固相合成法合成掺Mg2+的Li4Ti5O12/C复合材料。采用X-射线衍射、扫描电子显微镜、激光粒度分析和电性能测试等对复合材料进行表征,考察了Mg2+对于目标化合物结构和电化学性能的影响。结果表明,在C/3倍率下材料掺杂前后第二个循环的放电容量分别为145、162 mAh/g,循环30次后容量为138、150 mAh/g。电化学交流阻抗表明,掺杂后的材料阻抗Rct从180Ω减小到45Ω。掺杂后振实密度比掺杂前提高了0.27 g/cm3。Stoichiometric Mg-doped Li4Ti5O12/Canode material was synthesized through a simple solid state reaction in an inert atmosphere using magnesium lactate as dopant and part of carbon source and absolute alcohol as solvent.Li4Ti5O12 /C composites were characterized by XRD,SEM,Laser particle size analysis combined with electrochemical tests,and the effects of Mg2＋doping on the electrochemical and performance of anode materials were investigated.At 1/3 C discharge rate,the secondly reversible specific capacity of the Mg-doped Li4Ti5O12/C is nearly 20 mAh/g higher than that of the undoped one.After 30 cycles,the specific capacity of the former is 150 mAh/g,12 mAh/g higher than that of the latter.The impedance Rct of the Mg-doped material is 45Ω,while that of the undoped material is 180Ω.The tap density of Mg-doped material is also improved by 0.27 g/cm3 compared with undoped material.

关 键 词：乳酸镁 Li4Ti5O12/C 负极材料 掺杂 

分 类 号：TM912.9[电气工程—电力电子与电力传动]