正极材料Li_(1-x)La_xFe_(1-y)Mg_yPO_4/C合成及电化学性能研究  

Synthesis and electrochemical performance of Li_(1-x)La)xFe_(1-y)Mg_yPO_4/C cathode

作　　者：张皝[1] 张书诚[1] 徐云龙[1,2] 赵崇军[1,2] 

机构地区：[1]华东理工大学材料科学与工程学院,上海200237 [2]超细材料制备与应用教育部重点实验室,上海200237

出　　处：《电源技术》2012年第10期1445-1447,1473,共4页Chinese Journal of Power Sources

基　　金：上海市科学技术委员会"创新行动计划"(纳米专项0852nm 02300)

摘　　要：以La3+为Li位掺杂离子、Mg2+为Fe位掺杂离子,采用液相法合成双位掺杂的Li1-xLaxFe1-yMgyPO4/C(0≤x<1,0≤y<1)锂离子电池复合正极材料。通过X射线衍射法(XRD)和扫描电子显微镜法(SEM)研究材料的结构及形貌,恒流充放电测试电化学性能,考察Li1-xLaxFe1-yMgyPO4/C室温和低温电化学性能。结果表明:适量的La、Mg离子掺杂并未改变材料的结构;当La3+离子掺杂量为1%(摩尔分数)、Mg2+离子掺杂量为10%(摩尔分数)时,Li1-xLaxFe1-yMgyPO4/C的电化学性能最优。室温下,0.1 C首次充放电比容量达到155 m Ah/g。-20℃时,1 C、5 C、10 C较大倍率下首次充放电比容量为69、68、69 m Ah/g,低温下不同放电倍率下稳定性良好,拥有优异的低温循环稳定性。The multiple doping lithium ion battery composite cathode material Lil _,l_a ~Fel _~Vlg^PO,/＇C （0 ~〈x〈l, 0 〈~ y 〈1） was synthesized via a solution route using La3＋ and Mg2＋ as dopant ions. The samples were characterized by XRD, SEM and galvanostastic charge-discharge test, with the emphasis on low-temperature electrochemical performance. The results show that the samples are pure olive phase and the Lil_,La J=e~_~vlg^PO4/C has the best electrochemical performance when the La doping amount is 1% and the Mg is 10%. The initial discharge capacity of the sample delivers 155 mAh/g at 0.1 Cat room temperature. At --20 ~C, the sample also keeps 69, 68 and 69 mAh/g at 1 C, 5 C and 10 C. In addition, it shows excellent low-temperature cycle stability at different rates.

关 键 词：LIFEPO4 C 掺杂 低温 倍率稳定性 

分 类 号：TM912.9[电气工程—电力电子与电力传动]