Modified carbothermal reduction method for synthesis of LiFePO_4/C composite  

改进的碳热还原法合成LiFePO_4/C材料

作　　者：尹艳红[1,2] 李少玉[3] 闫琳琳[1,2] 张会双[1,2] 杨书廷[1,2] 

机构地区：[1]河南师范大学化学与环境科学学院,新乡453007 [2]河南省动力电源及关键材料工程技术研究中心,新乡453007 [3]河南师范大学物理与信息工程学院,新乡453007

出　　处：《Transactions of Nonferrous Metals Society of China》2012年第3期621-626,共6页中国有色金属学报（英文版）

基　　金：Project(21001041) supported by the National Natural Science Foundation of China;Project(102300410256) supported by Henan Province Foundation and Advanced Technology Research Program,China;Project(102102210183) supported by the Key Scientific and Technological Research Project of Henan Province,China;Project(2011B480005) supported by the Natural Science Research Project of Henan Province,China

摘　　要：With LiAc-2H2O as Li precursor,pure olivine phase LiFePO4/C was synthesized at a relatively low temperature（650 ℃） and short sintering period（4 h） by molten salt carbothermal reduction method.Scanning electron micrograph shows that particle size of the product is about 1μm,smaller than that of the sample synthesized with Li2CO3 as Li precursor.Electrochemical measurements prove that LiFePO4/C obtained from LiAc-2H2O shows high capacity.The initial discharge capacities are 148 mA-h/g at 0.5C rate and 115 mA-h/g at 5C rate,respectively.After 50 cycles,the capacity retention ratios are 93% and 89% at 0.5C rate and 5C rate,respectively.采用LiAc·2H2O作为锂源,利用熔盐碳热还原方法在较低的烧结温度和较短的烧结时间内(650℃,4h)合成纯相LiFePO4/C材料。扫描电镜照片显示这种方法合成的材料粒径大约为1μm,小于用Li2CO3作为锂源合成的材料。电化学测试表明,采用LiAc·2H2O作为锂源合成的材料表现出了高的放电容量和良好的倍率循环性能:在0.5C和5C倍率下,其首次放电容量分别为148mA.h/g和115mA.h/g;50次循环后,容量保持率分别为93%和89%。

关 键 词：LiFePO4/C composite molten salt carbothermal reduction Β-CYCLODEXTRIN 

分 类 号：TB332[一般工业技术—材料科学与工程]