锂离子电池正极材料Li1-xVxCryFe1-yPO4／C的制备及电化学性能的研究  

Preparation of Li_(1-x)V_xCr_yFe_(1-y)PO_4/C and study on its electrochemical performances

作　　者：宋士涛[1,2] 马培华[1] 李发强[1] 张昆[1,2] 王连亮[1,2] 

机构地区：[1]中国科学院青海盐湖研究所,青海西宁810008 [2]中国科学院研究生院,北京100039

出　　处：《功能材料》2008年第10期1694-1696,1699,共4页Journal of Functional Materials

基　　金：国家“十五”重点科技攻关计划滚动项目资助课题(2004BA602B-01);青海省重点科技攻关资助项目(2006-G-168)

摘　　要：采用高温固相法合成了Li1-xVxCryFe1-yPO4/C(x=0.01、0.02;y=0.01、0.02)锂离子电池正极材料,通过XRD、SEM、C-V和恒电流充放实验研究了不同掺杂量对产物结构和电化学性能的影响。研究表明,少量V和Cr的掺杂未影响到LiFePO4的晶体结构,但显著改善了它的电化学性。其中,Li0.99V0.01Cr0.02Fe0.98PO4/C材料具有更好的电化学性能,0.1C倍率放电时,首次放电容量达到163.8mAh/g,且循环性能良好。另外,对合成材料的红外光谱进行了研究和指认。Composites Li1-xVxCryFe1-yPO4/C （x=0. 01,0. 02; y=0. 01,0. 02） were synthesized by high temperature solid state reaction method. The samples were characterized by X-ray diffraction（XRD） and scanning electron microscope（SEM）, and their electrochemical performances were investigated including cycling behavior （C- V） and constant current charge-discharge experiment. The results indicate that the low concentration V and Cr dopant does not affect the structure of LiFePO4 but considerable improves its electrochemical performances. The Li0.99V0.01Cr0.02Fe0.98 PO4/C material showed better electrochemical performances than LiFePO4. At 0. 1C discharging rate, it is capable of delivering reversible specific capacity of 163.8mAh/g, with fairly stable cycleability. In addition, FT-IR spectroscopic studies for these materials were carried out and the vibrational bands were assigned.

关 键 词：磷酸铁锂 正极材料 离子掺杂 电化学性能 

分 类 号：TQ912.9[化学工程]