纳米Li_4Ti_5O_(12)中锂离子扩散系数的测定和解析  

Determination and analysis of lithium diffusion coefficient in Li_4Ti_5O_(12) cathode material

作　　者：杨旭[1] 郑少伟[1] 徐云龙[1] 张皝[1] 

机构地区：[1]华东理工大学材料科学与工程学院超细材料制备与应用教育部重点实验室,上海200237

出　　处：《电源技术》2013年第10期1736-1738,1741,共4页Chinese Journal of Power Sources

基　　金：上海市纳米科技专项(11nm 0500900)

摘　　要：以纳米Li4Ti50诬正极材料为研究对象，采用恒电位间歇滴定法（PITT）测定固相材料LiTiO5O12中u＋的扩散速率，解析u＋在纳米Li4Ti5O12充放电过程中的扩散行为。结果表明：测得的锂离子在活性材料中的扩散系数为10-12～10-12cm2／s数量级，主要集中在10-11，cm2／s附近。嵌锂过程中。Du＋先出现极小值，然后出现极大值；脱锂过程中，阱先出现极大值，然后出现极小值。在同一电位下，充电过程（脱锂）的锂离子扩散系数大于放电过程（嵌锂）的锂离子扩散系数。Nanostructured Li4TisO12 was used as a cathode material for the study. The chemical diffusion coefficient of Li-ion in Li4TisO12 was measured by potentiostatic intermittent titration technique （Pll-r） method and Li＋ diffusion behavior in nano Li4TisO12 was analyzed during the process of charging and discharging. The result shows that the diffusion coefficient of lithium ion in active material ranges from 10-~2 to 10-~~ cm2/s, and mainly concentrates in 10-＂ cm2/s. In the process of Li~ deintercalation, the diffusion coefficient comes to the minimum firstly, and then rises to a great value. While in the process of Li~ intercalation, the maximum comes first, and then decreases to a minimum. At the same potential, the charging process （lithium intercalation） of lithium ion exhibits a higher diffusion coefficient than the discharging process.

关 键 词：Li4Tis012 扩散系数 Pitt法 

分 类 号：TM912.9[电气工程—电力电子与电力传动]