球形尖晶石LiMn_2O_4的制备及性能  

Preparation and characterization of spherical spinel LiMn_2O_4

作　　者：李永坤[1] 黄可龙[1] 刘素琴[1] 王洪恩[1] 

机构地区：[1]中南大学化学化工学院,长沙410083

出　　处：《功能材料与器件学报》2007年第4期389-393,共5页Journal of Functional Materials and Devices

基　　金：教育部博士点基金资助项目(No.20030533001)

摘　　要：通过氧化还原法在室温下制备出球形MnO2前驱体,以LiOH.H2O为锂源,按照一定锂锰摩尔比混合,在750℃下焙烧8h,得到球形尖晶石LiMn2O4。采用X射线衍射和扫描电镜对MnO2和LiMn2O4进行了表征,并对LiMn2O4样品做了充放电性能及循环性能测试。结果表明:合成的样品以球形颗粒存在,粒度大小均匀,分散性和流动性好;首次充放电比容量分别为130.5和128.2mAh.g-1,充放电效率为98.2%,50次循环后容量保持率为90%,球形LiMn2O4具有较高的比容量和优良的循环性能。Spherical MnO2 powders were prepared by the redox method at room temperature. The spherical spinel LiMn2O4 powders were synthesized by sintering the MnO2 precursor mixed with LiOH · H2O by controlling the molar ratio of metal ions Li ＋ ： Mn2 ＋ at 750℃ for 8h. The structures and morphologies of MnO2 and LiMn2O4 were characterized by XRD and SEM. And the spherical LiMn2O4 cathode material was measured by electrochemical test of charge -discharge. The results show that the spherical LiMn2O4 particles which are sized as 41μm uniformly have excellent dispersty and mobility. The initial charge capacity and discharge capacity of sample are 130.5 mAh·g^-1 and 128.2 mAh · g^-1 respectively with the charge - discharge efficiency of 98.2%. After 50 cycles, the retention of capacity is 90%. The spherical spinel LiMn2O4 has both higher specific capacity and excellent cycleability.

关 键 词：MNO2 尖晶石LIMN2O4 球形 电化学性能 

分 类 号：TM912.9[电气工程—电力电子与电力传动] O614.111[理学—无机化学]