稀土镧掺杂层状锰酸锂正极材料的制备与性能  

Synthesis and Performances of Layered Lithium Manganese Oxides of Rare Earth Doped Cathode Materials

作　　者：赵桂网[1] 何建平[1] 张传香[1] 潘科亮[1] 周建华[1] 

机构地区：[1]南京航空航天大学,江苏南京210016

出　　处：《稀有金属材料与工程》2008年第4期709-712,共4页Rare Metal Materials and Engineering

基　　金：江苏省高新技术项目(BG2005009)

摘　　要：采用溶胶凝胶法制备层状LiMnO2,并掺杂不同比例的稀土元素进行改性。XRD分析结果表明,掺杂镧元素的层状锰酸锂呈斜方晶系,纯度较高。SEM照片显示这种产物为层状结构,且粒度大小分布较为均匀。用循环充放电测试考察了产物的电化学性能,结果显示掺杂6%La的层状锰酸锂正极材料的初次放电比容量为128mAh/g,但循环稳定性较差;而掺杂了4%La的层状锰酸锂则表现了良好的循环稳定性,首次放电比容量达到了102mAh/g,多次充放电之后容量基本没有衰减,仍然能保持较高的比容量。从交流阻抗数据分析,掺镧量为4%的样品扩散阻抗较小,充放电可逆性较好。Layered lithium manganese oxides were prepared by sol-gel method. Various concentrations of Lanthanum （La） were doped. XRD results reveal that the samples possess orthorhombic structure with a high purity. SEM images show that all the La doped LiMnO2 samples present well-ordered layered structure with uniform particle sizes. The electrochemical galvanostatic charge-discharge cycling performances show that the discharge capacity of 6%La doped LiMnO2 is 128 mAh/g, but the cycle performance is not agreeable. The capacities of 4%La doped samples are good in charge-discharge cycling test. The specific capacity remains stable even after several cycles The diffusion impedance of 4%La doped LiMnO2 is smaller and the cycle performance is better.

关 键 词：层状LIMNO2 溶胶凝胶法 稀土掺杂 

分 类 号：TM912.9[电气工程—电力电子与电力传动]