不同锂锰比尖晶石型LiMn_2O_4的结构与电化学性能的分析  

Analysis of series of Li∶2 Mn ratio on the electrochemical properties of spinel LiMn_2O_4

作　　者：钟盛文[1] 李培植[1] 梅桂[1] 李艳[2] 胡杨[2] 刘庆国[2] 

机构地区：[1]北京科技大学固体电解质研究室,北京100083 [2]江西理工大学材料与化学工程学院,江西赣州341000

出　　处：《电源技术》2006年第5期366-369,373,共5页Chinese Journal of Power Sources

摘　　要：分析了系列不同锂锰比对尖晶石型LiMn2O4性能的的影响。并对样品进行TG-DTA(热重/差热分析仪)、XRD(X射线衍射光谱)、SEM(扫描电镜)与电性能测试。研究结果表明:Li∶2Mn为1.00～1.50时,都可以得到尖晶石结构的LiMn2O4;当Li∶2Mn比值为1时,LiMn2O4的晶粒单体形态表现为规则的八面体状;随Li∶2Mn比值增大,LiMn2O4晶胞轴长有变小趋势,电化学稳定性有一定增强,比容量和电循环性能均有所改善,Li∶2Mn比值约为1.04～1.05时,其电化学性能表现较好;随着锂锰比的增加,杂相也相应增加,LiMn2O4由规则粒状渐变为团块状。由于杂质相含量的增加及LiMn2O4晶格变形增强,当Li∶2Mn比大于1.2时,电化学性能也明显变差。The influence of series of different Li ： 2 Mn ratio on the properties of spinel LiMn2O4 was analyzed and the samples were characterized by TG-DTA （ thermogravimetryand and differential thermal analysis ）, XRD （ X ray diffraction ）, SEM （ scanning electronic microscopy ）and the electric properties test. The results show that the LiMn2O4 with spinel structure could be reached when the Li ： 2 Mn ratio was in the range of 1.00-1.50. The single grain shape of LiMn2O4 represented regular octahedron figure as Li ： 2 Mn ratio 1. The axis length of LiMn2O4 crystal lattice became shorter with the increase of Li ： 2 Mn ratio. The electrochemical stability was intensified. The specific capacity and cycle property were improved. Especially when the Li ： 2 Mn was about 1.04-1.05, the anode materials had a better electrochemical property. Simultaneously, the content of impurity phases also raised with the increase of Li ： 2 Mn ratio. The figure of LiMn2O4 structure was from granular to conglomeration in shape. While the impurity phase and the lattice distortion of LiMn2O4 were increased, the electrochemical property deteriorated obviously when Li ; 2 Mn ratio was greater than 1.2.

关 键 词：LIMN2O4 Li:2Mn比 晶体结构 电化学性能 

分 类 号：TM912.9[电气工程—电力电子与电力传动]