物理化学学报 >> 2010, Vol. 26 >> Issue (03): 573-577.doi: 10.3866/PKU.WHXB20100303

电化学 上一篇    下一篇

一种新的流变相法制备锂离子电池纳米-LiVOPO4正极材料

熊利芝, 何则强   

  1. 吉首大学生物资源与环境科学学院, 湖南 吉首 416000; 中南大学化学化工学院, 长沙 410083
  • 收稿日期:2009-10-18 修回日期:2009-12-16 发布日期:2010-03-03
  • 通讯作者: 何则强 E-mail:csuhzq@163.com

A New Rheological Phase Route to Synthesize Nano-LiVOPO4 Cathode Material for LithiumIon Batteries

XIONG Li-Zhi, HE Ze-Qiang   

  1. College of Biology and Environmental Sciences, Jishou University, Jishou 416000, Hunan Province, P. R. China; College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China
  • Received:2009-10-18 Revised:2009-12-16 Published:2010-03-03
  • Contact: HE Ze-Qiang E-mail:csuhzq@163.com

摘要:

采用新型流变相法制备锂离子电池正极材料纳米-LiVOPO4. 采用X射线衍射、扫描电子显微镜以及电化学测试等手段对LiVOPO4的微观结构、表面形貌和电化学性能进行了表征. 结果表明, 采用流变相法制备的LiVOPO4由粒径大约在10-60 nm的小颗粒组成. 首次放电容量, 首次充电容量以及库仑效率分别为135.7 mAh·g-1, 145.8 mAh·g-1和93.0%. 0.1C (1C=160 mA·g-1)放电时, 60次循环后, 放电容量保持在134.2 mAh·g-1, 为首次放电容量的98.9%, 平均每次循环的容量损失仅为0.018%. 而1.0C和2.0C放电时的放电容量达到0.1C放电容量的96.5%和91.6%. 随着放电次数的增加, 电荷转移阻抗增加, 而锂离子在电极中的扩散系数达到10-11 cm2·s-1数量级. 实验结果显示采用流变相法制备的LiVOPO4是一种容量高、循环性能好、倍率性能好的锂离子电池正极材料.

关键词: 锂离子电池, 流变相法, LiVOPO4, 倍率性能, 扩散系数

Abstract:

A novel lithium-ion battery cathode material, nano-LiVOPO4, was synthesized by a new rheological phase method. The microstructure, surface morphology, and electrochemical properties were characterized by various electrochemicalmethods in combination withX-ray diffraction (XRD) and scanning electron microscopy (SEM). Results show that the orthorhombic LiVOPO4, obtained by this rheological phase method, is made up of 10-60 nm particles. The first discharge capacity, charge capacity, and columbic efficiency of LiVOPO4 were found to be 135.7 mAh·g-1, 145.8 mAh·g-1, and 93.0%, respectively. After 60 cycles, the discharge capacity remained 134.2 mAh·g-1, at 98.9% of the first discharge capacity, and the capacity loss per cycle was only 0.018%at 0.1C (1C=160 mA·g-1).More than 96.5% and 91.6% of the discharge capacity at 0.1C were maintained at 1.0C and 2.0C, respectively. The charge transfer resistance increased with the increase of the cycle number and the diffusion coefficient of lithium ion in the nano-LiVOPO4 was in the order of 10-11 cm2·s-1. Experimental results suggest that the rheological phase method is a good route for the synthesis of LiVOPO4 cathode material of high capacity, good cycling performance, and good current rate capability for lithiumion batteries.

Key words: Lithium ion battery, Rheological phase method, LiVOPO4, Current rate capability, Diffusion coefficient

MSC2000: 

  • O646