掺杂Mo的LiFePO4正极材料的电化学性能  

Electrochemical Properties of Mo-Doped LiFePO_4 Cathode Material

作　　者：陈宇[1] 王忠丽[1] 于春洋[1] 夏定国[1] 吴自玉[2] 

机构地区：[1]北京工业大学环境与能源工程学院,北京100022 [2]中国科学院高能物理研究所,北京同步辐射实验室,北京100049

出　　处：《物理化学学报》2008年第8期1498-1502,共5页Acta Physico-Chimica Sinica

基　　金：北京市属市管高等学校人才强教计划;北京市自然科学基金(207001)资助

摘　　要：通过固相法以(NH4)6Mo7O24·4H2O为钼源,在氮气气氛下合成出掺杂Mo的LiFePO4正极材料.采用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、扩展X射线吸收精细结构(EXAFS)和正电子湮没进行结构表征,通过不同放电倍率研究掺Mo的LiFePO4电化学性能.结果表明,掺Mo的LiFePO4呈橄榄石结构,Mo6+同时占据着Fe位及Li位,提高了LiFePO4的电导率,1C放电可逆容量为141mAh·g-1,表现出良好的电化学性能.Mo-doped LiFePO4 was prepared using （NH4）6Mo7O24·4H2O as doping starting material by solid state method under N2 atmosphere. The Mo-doped LiFePO4 samples were characterized by X-ray diffraction, scanning electron microscope, X-ray photoelectron spectrum, extended X-ray absorption fine structure, positron annihilation technique, and electrochemical performance testing at different discharge rates. The results showed that Mo-doped LiFePO4 preserved pure olivine structure. Mo^6＋ occupied Fe site and Li site simultaneously and the electronic conductivity of LiFePO4 increased. The Mo-doped LiFePO4 had a reversible capacity of 141 mAh·g^-1 at lC discharge rate, and showed good electrochemical properties.

关 键 词：磷酸亚铁锂 固相法 离子掺杂 电子电导率 

分 类 号：TM912[电气工程—电力电子与电力传动]