生物-共沉淀法合成高性能磷酸铁锂介孔复合材料

The Preparation of LiFePO_4 Mesoporous Composite Material by Bio-Copreapitation Method

本文利用生物-共沉淀新方法合成磷酸铁锂材料。以微生物为模板与金属离子和磷酸根通过矿化反应和共沉淀反应,形成沉淀物。经热处理后得到具有介孔结构的LiFePO4/C复合材料,其介孔尺寸在3～25nm之间;合成材料在0.1C时其初次放电比容量达到150mAh/g;高倍率下具有良好的循环性能,经过100次充放电循环后,其比容量保持率高达95%;充放电平台稳定,其电压稳定在3.4V左右;循环伏安测试结果显示,电池反应在3.4V左右极化现象不明显。合成材料其电化学性能的提高主要是由于其介孔结构和原位复合碳的存在,从而可显著提高锂离子的传导率和电子的电导率。本方法对制备高性能锂离子电池正极材料具有重要的应用价值。

This paper used a novel bio--coprecipitation approach to prepare LiFePO4. Microorganism was used as template, and precipitate was obtained with metal ion and phosphate after mineralization reaction and coprecipitation process. LiFePO4/C composite material was gained by heat treatment that have mesoporous structure,the mesoporous size of material is 3～25nm. The material of discharge ca- pacifies is 150 mA charging platform hg-1 at O. 1C. After 100 is very steady and volta cycles ,the capacity retention ratio is 95 %. Charging and dis- ge is about 3.4V. Cyclic Voltammetry display that the po- larization phenomenon of material is not obvious. The Lithium ion conductivity and electronic conduc tivity was enhanced by existing mesoporous structure and in situ composite carbon in material. LiFe P04/C composite material synthetized by this approach has the important application value.