物理化学学报 >> 2005, Vol. 21 >> Issue (09): 957-960.doi: 10.3866/PKU.WHXB20050903

研究论文 上一篇    下一篇

LiMn2O4中锂离子扩散系数与充/放电次数的关系

唐新村; 黄伯云; 贺跃辉   

  1. 中南大学化学化工学院,长沙 410083; 中南大学粉末冶金国家重点实验室,长沙 410083
  • 收稿日期:2004-12-22 修回日期:2005-01-26 发布日期:2005-09-15
  • 通讯作者: 唐新村 E-mail:tangxc@csu.edu.cn

Dependence of Li+ Diffusion Coefficients in LiMn2O4 on Charge/Discharge Cycles

TANG Xin-cun; HUANG Bo-yun; HE Yue-hui   

  1. College of Chemistry and Chemical Engineering, Central South University; State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083
  • Received:2004-12-22 Revised:2005-01-26 Published:2005-09-15
  • Contact: TANG Xin-cun E-mail:tangxc@csu.edu.cn

摘要: 通过容量间歇滴定技术(CITT)对不同电压、不同循环次数下,锂离子在尖晶石LiMn2O4中的固相扩散系数进行了研究. 结果表明,锂离子在尖晶石LiMn2O4正极材料中的固相扩散系数在3.95 V和4.12 V左右存在两个极小峰,随着循环次数的增加,这两个峰逐渐平坦,并且整体上固相扩散系数呈增大趋势,表明锂离子在LiMn2O4中重复脱/嵌时具有自我增强扩散的能力.

关键词: 容量间歇滴定技术, 固相扩散系数, LiMn2O4, 锂离子电池

Abstract: The solid diffusion coefficient of lithium-ion in spinel LiMn2O4 cathode material has been investigated by the capacity intermittent titration technique (CITT) at different voltages and at different charge/discharge cycles. Results show that there are two minimum peaks in the curves of the solid diffusion coefficient (D) vs voltage (E) at 3.95 V and 4.12 V in the voltage range from 3.85 V to 4.30 V. The curves of lgD-E for the first 20 cycles show that the two minimum peaks are gradually flatted out and the values of solid diffusion coefficient tend to increase when the cycling number increases. The results suggest that LiMn2O4 cathode material has the ability of self-diffusion-enhance during intercalation/deintercalation of lithium-ion.

Key words: Capacity intermittent titration technique, Solid diffusion coefficient, LiMn2O4, Lithium-ion batteries