尖晶石LiMn_2O_4表面包覆TiO_2与LiTi_2(PO_4)_3及其性质研究  

Preparation and Characterization of LiMn_2O_4 Coated by TiO_2 and LiTi_2(PO_4)_3

作　　者：吴显明[1,2] 陈上[1,2] 麦发任[1] 赵俊海[1] 何海亮[1] 

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

出　　处：《人工晶体学报》2013年第7期1410-1413,1428,共5页Journal of Synthetic Crystals

基　　金：国家自然科学基金(21263004)

摘　　要：采用湿化学法对LiMn2O4进行TiO2及LiTi2(PO4)3表面包覆。采用X射线衍射仪、扫描电镜、恒电流充放电等技术对合成产物进行物相、形貌和电化学分析。结果表明:TiO2及LiTi2(PO4)3包覆LiMn2O4与未包覆LiMn2O4具有相似的X射线衍射结果。室温和55℃以0.5 C倍率充放电循环20次后,TiO2包覆LiMn2O4的容量保持率分别为98.2%和95.3%,LiTi2(PO4)3包覆LiMn2O4的容量保持率分别为99.1%和96.8%,高于未包覆LiMn2O4的94.6%和92.2%。表面包覆LiTi2(PO4)3后LiMn2O4的锂离子扩散系数变化不大,但包覆TiO2后的锂离子扩散系数略有下降。TiO2 and LiTi2（PO4） 3 coated LiMn2O4 was prepared by wet chemical route.The phase,surface morphology,and electrochemical properties of the prepared powders were characterized by X-ray diffraction,scanning electron micrograph,and galvanostatic charge-discharge experiments.TiO2 and LiTi2（PO4） 3 coated LiMn2O4 has similar X-ray diffraction patterns as LiMn2O4.When cycled at room temperature and 55 ℃ for 20 times at the charge-discharge rate of 0.5 C,the capacity retention rates of TiO2 coated LiMn2O4 are 98.2% and 95.3%,and those for the LiTi2（PO4） 3 coated LiMn2O4 are 99.1% and 96.8%,which are considerably higher than the values of 94.6% and 92.2% for the uncoated LiMn2O4.LiTi2（PO4） 3 coated LiMn2O4 has almost the same Li diffusion coefficient as LiMn2O4,while that of TiO2 coated LiMn2O4 is smaller than the uncoated LiMn2O4.

关 键 词：LIMN2O4 锂离子电池 包覆 容量保持率 扩散系数 

分 类 号：TM912.9[电气工程—电力电子与电力传动]