四氧化三锰制备尖晶石锰酸锂及电化学性能研究  

Preparation and electrochemical properties of spinel LiMn_2O_4 by using Mn_3O_4

作　　者：陈守彬[1] 吴显明[1,2] 陈上[1,2] 刘志雄[1] 丁其晨[1] 

机构地区：[1]吉首大学化学化工学院,湖南吉首416000 [2]湘西自治州矿产与新材料技术创新服务中心,湖南吉首416000

出　　处：《应用化工》2015年第10期1791-1795,共5页Applied Chemical Industry

基　　金：国家自然科学基金项目(21263004)

摘　　要：采用金属锰粉悬浮液氧化法、焙烧法、两步法制备Mn3O4。根据Li2CO3/Mn3O4混合粉体的TG-DTA分析结果,以高温固相法合成尖晶石LiMn2O4。通过X射线衍射、扫描电子显微镜、恒流充放电技术及交流阻抗,对这合成样品尖晶石LiMn2O4的物相、形貌以及电化学能进行检测分析,采用电位跃迁法测试计算出尖晶石LiMn2O4电极材料的扩散系数。结果表明,用3种不同方法制备的Mn3O4都能合成颗粒大小均匀的尖晶石LiMn2O4,在室温下以0.2 C倍率充放电循环30次时,以悬浮液氧化法制备Mn3O4合成的尖晶石LiMn2O4首次放电比容量和容量保持率分别为130.0 m A·h/g和98.1%,优于另外两种方法制备Mn3O4合成的尖晶石LiMn2O4。以不同Mn3O4合成尖晶石LiMn2O4电极材料的扩散系数DLi+分别为:7.78×10-11,5.01×10-11,3.26×10-11cm2/s。Mn3O4 were prepared by oxidation with suspension solution,baking process and tow-step method. Based on the TG-DTA analysis for Li2CO3/ Mn3O4 mixture power,spinel LiMn2O4 was synthesized via solid-phase method. The phase identification,surface morphology and electrochemical properties of the three kinds of the synthesized powders were characterized by means of XRD,SEM,galvanostatic chargedischarge experiments,EIS and PSCA. The results show Mn3O4 prepared by three different methods can synthesize spinel LiMn2O4 and LiMn2O4 powders are uniform and show best crystallization. When cycled at room temperature for 30 times at the charge-discharge rate of 0. 2,LiMn2O4 prepared by Mn3O4 using oxidation with suspension solution shows the highest initial charge specific capacity and capacity retention of 130. 0 m A·h / g and 98. 1%. The diffusion coefficient of lithium ion of LiMn2O4 are 7. 78 ×10^-11,5. 01 ×10^-11,3. 26 ×10^-11cm^2/ s,respectively.

关 键 词：四氧化三锰 正极材料 锰酸锂 电化学性能 

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