F-掺杂锂钒氧化物的合成及其电化学性能  

Synthesis and electrochemical performances of fluorine doped lithium vanadium oxides

作　　者：顾军[1] 李娟[1] 

机构地区：[1]新疆大学化学化工学院,新疆乌鲁木齐830046

出　　处：《电源技术》2009年第3期207-209,共3页Chinese Journal of Power Sources

基　　金：国家自然基金(20663006);新疆自治区高校科研计划项目(XJEDU2006S206);新疆大学校院联合项目(070196)资助。

摘　　要：以LiF、LiOH和NH4VO3为原料,采用柠檬酸溶胶-凝胶法合成了F掺杂锂钒氧化物LiV3F2xO8-x(x=0.01、0.025、0.05、0.1)。利用X射线衍射(XRD)、透射电镜(TEM)等测试手段对合成材料进行了表征,通过恒流充放电、循环伏安和交流阻抗技术研究了材料的电化学性能。结果表明,所得样品的结晶性较好、结构完整。F的掺杂能有效提高锂钒氧化物的首次充放电容量,但如果掺杂量过多,则会损坏材料的循环充放电性能。在所有掺杂样品中,理论组成为LiV3F0.05O7.975的样品表现出较好的充放电循环性能。Layered-type compounds of lithium vanadium oxides LiV3F2xO8-x （ x=0.01,0.025,0.05,0.1） were synthesized by the sol-gel technique of citric acid with LiF, LiOH and NH4VO3 as raw materials. The synthesized samples were characterized by XRD, TEM,et al. The galvanostatic charge-discharge, AC impedance technique and cyclic voltammetry tests were also used to investigate the electrochemical properties of doped materials. The results show that the products have high crystallinity and perfect layered-type structure. The initial charge-discharge capacities of fluorine doped samples have better doping effect, but their cycling performance is decayed rapidly with the increase of F ion content. The charge-discharge performance and cyclestability of LiV3F0.05T.7.975 sample are the best in all doped samples.

关 键 词：锂离子电池 锂钒氧化物 F掺杂 

分 类 号：TM912.9[电气工程—电力电子与电力传动]