不同锰源制备尖晶石LiMn_2O_4及电化学性能研究  

Preparation and electrochemical properties of spinel LiMn_2O_4 by using different manganese sources

作　　者：陈守彬[1] 吴显明[1,2] 陈上[1,2] 丁其晨[1] 何海亮[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》2016年第1期18-21,25,共5页Applied Chemical Industry

基　　金：国家自然科学基金项目(21263004)

摘　　要：分别用化学二氧化锰、电解二氧化锰、MnCO_3和Mn_3O_4为锰源,通过高温固相法合成尖晶石LiMn_2O_4。采用X射线衍射仪、扫描电子显微镜、恒电流充放电技术、交流阻抗及电位阶跃法,对合成的尖晶石LiMn_2O_4物相、形貌以及电化学性能进行检测分析。结果表明,由Mn_3O_4制备的LiMn_2O_4的X射线衍射峰强度最大且粒度较为均匀。在室温条件下,以0.2C倍率充放电循环20次,Mn_3O_4制备的LiMn_2O_4首次充放电比容量为128.3 mA·h/g,容量保持率为97.1%,优于另外三种锰源作为原料合成的尖晶石LiMn_2O_4。化学二氧化锰、电解二氧化锰、MnCO_3、Mn_3O_4合成尖晶石LiMn_2O_4电极材料的扩散系数DLi+分别为2.26×10^(-11),4.54×10^(-11),0.83×10^(-11),8.25×10^(-11)cm^2/s。Spinel LiMn_2O_4 was synthesized via solid-phase method with different manganese sources of CMD,EMD,MnCO_3 and Mn_3O_4. The phase identification,surface morphology and electrochemical properties of the four kinds of the synthesized powders were characterized by means of XRD,SEM,galvanostatic charge-discharge experiments,EIS and PSCA. The results show that LiMn_2O_4 powders prepared by Mn_3O_4 are uniform and show best crystallization. When cycled at room temperature for 20 times at the charge-discharge rate of 0. 2C,LiMn_2O_4 prepared by Mn_3O_4 shows the highest initial charge specific capacity and capacity retention of 128. 3 mA · h/g and 97. 1%. The diffusion coefficient of lithium ion of LiMn_2O_4 synthesized by CMD,EMD,MnCO_3 and Mn_3O_4are 2. 26 × 10^（-11）,4. 54 × 10^（-11）,0. 83 × 10^（-11）,8. 25 ×10^（-11）cm^2/ s.

关 键 词：锂离子电池 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]