Nb^(5+)掺杂LiFePO_4/C的反应挤出合成  

Synthesis of LiFePO_4 /C doped with Nb^(5+) by reaction extrusion

作　　者：刘旭恒[1,2] 黄少波[2] 赵中伟[2] 王德志[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学冶金科学与工程学院,长沙410083

出　　处：《中国有色金属学报》2012年第11期3236-3240,共5页The Chinese Journal of Nonferrous Metals

基　　金：中央高校基本科研业务费专项资金资助项目;中南大学博士后基金资助项目

摘　　要：以LiOH.H2O、FeC2O4.2H2O和P2O5为原料,以草酸铌为添加剂,采用反应挤出法合成Li1 5xNbxFePO4/C材料;采用X射线衍射(XRD)、扫描电镜(SEM)、循环伏安(CV)和充放电测试研究不同Nb5+掺杂量对Li1 5xNbxFePO4/C材料结构、形貌以及电化学性能的影响。结果表明,适量的Nb5+掺杂不会改变材料的结构和形貌;Nb5+掺杂可以有效减小电极的极化,其中Li0.97Nb0.006FePO4/C表现出最佳的电化学性能,在0.2C、0.5C、1C和2C倍率下的首次放电比容量分别为162.9、148.9、141.7和137.1 mA.h/g;材料循环性能良好,经10次循环后,材料的放电比容量都保持在99%以上。Li1-5x Nb x FePO4 /C material was synthesized by reaction extrusion using LiOH·H2O,FeC2O4 ·2H2O and P2O 5 as raw materials and niobium oxalate as additive.The effects of Nb 5＋ content on the structure,morphology and electrochemical properties were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM） analysis and electrochemical tests.The results show that appropriately doping Nb 5＋ can reduce the electrode polarization effectively without serious effects on structure and morphology.Li 0.97 Nb 0.006 FePO4 /C,exhibiting the best electrochemical properties,has initial discharge capacities of 162.9,148.9,141.7 and 137.1 mA·h/g at 0.2C,0.5C,1C and 2C rate, respectively,and the discharge capacities remain above 99% after 10 cycles.

关 键 词：锂离子电池 磷酸铁锂 反应挤出 Nb掺杂 

分 类 号：TM912.9[电气工程—电力电子与电力传动]