锂离子电池正极材料LiMn_2O_4的改性研究  

The modification of cathode material LiMn_2O_4 for lithium-ion batteries

作　　者：周艺峰[1] 聂王焰[1] 陈春华[2] 水江澜[2] 

机构地区：[1]安徽大学化学化工学院,安徽合肥230039 [2]中国科学技术大学材料科学与工程系,安徽合肥230026

出　　处：《功能材料》2006年第9期1381-1385,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(50372064)

摘　　要：分别采用过渡元素掺杂和不同聚合物(聚丙烯晴和聚噻吩)包覆的方法对锂离子电池用正极材料LiMn2O4进行改性,研究了改性前后LiMn2O4的电化学性能。结果表明采用掺杂改性和聚合物包覆改性都可以提高LiMn2O4的电化学性能,减缓容量衰减。但单纯用一种方法改性效果都不理想,而将两种方法结合起来使用则不仅能有效地阻止电池在室温下的容量衰减(在前60个循环中,改性前电池的放电容量从119.1mAh/g下降到99.6mAh/g,平均每个循环的容量衰减率为0.27%,经Cr元素掺杂再用聚丙烯腈包覆后电池的放电容量从94.6mAh/g下降到91.8mAh/g,平均每个循环的容量衰减率为0.05%),而且使电池在高温下(60oC)也有很好的循环性能。Spinel LiMn2O4 is regarded as the most promising cathode material for lithium-ion batteries because of its low cost and environmental friendly nature over LiCoO2. In this paper, the electrochemical performance of LiMn2O4 was improved by doping with chromium and coating with polymers. Its electrochemical characteristics were measured before and after the modifications. The results showed that both of coating and doping could suppress the capacity fading of LiMn2O4 and improve its electrochemical characteristics. Nevertheless, only one way cannot achieve the best effect until both are used. With the combination of these two modification approaches we can not only stop the capacity fade of LiMn2O4 at room temperature, but also stabilize its cycling performance at high temperature.

关 键 词：锂离子电池 锰酸锂 掺杂 包覆 改性研究 

分 类 号：TM912.9[电气工程—电力电子与电力传动]