Li_3Ti_4CrMO_(12)负极材料制备及其电化学性能  

Preparation and Electrochemical Performance of Li_3Ti_4CrMO_(12) Anode Materials for Lithium Ion Batteries

作　　者：李南[1,2] 任婕[1] 章冬云[1] 马紫峰[1,2,3] 

机构地区：[1]上海应用技术学院材料科学与工程学院,上海201418 [2]上海交通大学化学工程系,上海200240 [3]上海电化学能源器件工程技术研究中心,上海200240

出　　处：《上海应用技术学院学报（自然科学版）》2015年第4期321-326,共6页Journal of Shanghai Institute of Technology: Natural Science

基　　金：国家自然科学基金资助项目(21203120);上海市科委能力建设资助项目(14520503100);上海市教委科研创新资助项目(15ZZ095);上海张江国家自主创新示范区专项发展资金(201310-JD-B2-009)

摘　　要：基于Li_4Ti_5O_（12）结构,设计双离子取代反应,制备了3种新型锂离子负极材料Li_3Ti_4CrMO_（12）（M=Ni、Ca、Mg）,这些取代型负极材料具有与钛酸锂相同的晶体结构.使用球磨、喷雾造粒以及固相合成工艺制备出一次粒子为200~300nm,二次颗粒为多孔球形的新型负极材料Li_3Ti_4CrMO_（12）,并对其电化学性能进行了测试.循环充放电试验结果表明,制备的3种材料中,镁铬钛酸锂（Li_3Ti_4CrMgO_（12））具有较高的放电比容量和较好的循环稳定性,0.2C下首次放电比容量达158.6mA·h/g.10次循环后,放电容量为148.1mA·h/g,充电容量为149.1mA·h/g,容量保持率和库伦效率均在99%以上,显示了潜在的应用价值.循环伏安（CV）和电化学阻抗谱（EIS）分析表明,上述优良性能来自于Mg、Cr取代后导致的材料界面电阻的下降.Based on the crystal structure of Li_4Ti_5O_（12）,three new compounds with chemical composition of Li_3Ti_4CrMO_（12）（M=Ni、Ca、Mg）were synthesized by replacing Li and Ti ions with Cr and M ions.The newly prepared anodic materials showed similar crystal structure to their mother compound Li_4Ti_5O_（12）.Porous spheres of the anodic materials with grain size around 200—300 nm were obtained through a combined method of nano grinding and spray drying.The electrochemical tests revealed different results.Among the three kinds of anodic materials,Li_3Ti_4CrMgO_（12） presents the best electrochemical performance.The initial charging capacity attains 158.6mA·h/g,which is very close to its theoretical capacity.After10 cycles the discharge capacity remains 148.1 mA·h/g,while the charge capacity is 149.1 mA·h/g.Such cyclic performance creates good capacity retention and high columbic efficiency（〉99%）and suggests great potential for industrial application.The subsequent cyclic voltammetry（CV）and electrochemicalimpedance spectroscopy（EIS） measurements further illustrated that the above-mentioned good electrochemical behaviors stemmed from the decline in the interfacial resistance generated by the replacement of Li/Ti with Mg/Cr.

关 键 词：负极材料 钛酸锂 电化学性能 交流阻抗 

分 类 号：TQ131.11[化学工程—无机化工] TM912[电气工程—电力电子与电力传动]