设为首页 联系我们 加入收藏

当前位置: 网站首页 期刊分类目录 2016第5期 正文

聚吡咯包覆尖晶石LiMn2O4微球的合成及其电化学储锂性能

作者:时间:2016-10-11点击数:

PDF全文下载:2016050533

张堃, 李桂村*

(青岛科技大学 材料科学与工程学院,山东 青岛 266042)

摘要: 利用共沉淀法合成MnCO3微球与Li2CO3进行固相反应制备了尖晶石LiMn2O4微球。通过吡咯在LiMn2O4表面上进行化学氧化聚合合成了聚吡咯包覆LiMn2O4微球(PPyLiMn2O4)。聚吡咯包覆层不仅可以提高LiMn2O4微球的电子导电率,而且其本身像一个电容器。这种结构特点有利于提高LiMn2O4的容量,倍率性能和高倍率循环稳定性。通过循环伏安(CV)、交流阻抗(EIS)和恒流充放电等方法测试了电极材料的电化学性能,研究表明:PPyLiMn2O4显示了比LiMn2O4微球更好的电化学储锂性能,包括高比容量(118-4 mA·h·g-1)、高倍率性能(5 C,104.5 mA·h ·g-1)。

关键词:  锂离子电池; 锰酸锂; 聚吡咯; 包覆

中图分类号:  TM 912.9文献标志码: A

Synthesis and Electrochemical Performance of Spinel LiMn2O4Surface Coated with Polypyrrole

 ZHANG Kun, LI Guicun

(CollegeofMaterials Scienceand Engineering,QingdaoUniversityof Science and Technology,Qingdao266042,China)

Abstract: Spinel lithium manganese oxide (LiMn2O4) microspheres have been prepared by solid state reaction between Li2CO3and MnCO3microspheres obtained by coprecipitation method. Polypyrrole coated LiMn2O4microspheres (PPy@LiMn2O4) have been synthesized by the chemical oxidation polymerization of pyrrole on the surfaces of LiMn2O4microspheres. The polypyrrole coating can not only increase the electronic conductivity of LiMn2O4microspheres, but also behaves like a capacitor. The structure features are favorable for improving the capacity density, rate capability and cycling stability of LiMn2O4. Electrochemical properties have been studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge tests at various current rates. When used as cathode materials, PPy@LiMn2O4exhibit better electrochemical lithium storage performances including high specific capacity (118.4 mA·h·g-1) and rate capability (104.5 mA·h·g-1 at 5 C).

Key words: Liion batteries; lithium manganese oxide; polypyrrole; surface coating

收稿日期: 20150819

作者简介: 张堃(1989—),男,硕士研究生.*通信联系人.

文章编号: 16726987(2016)05053306; DOI: 10.16351/j.16726987.2016.05.012

Copyright © 2011-2017 青岛科技大学学报 (自然科学版)