【摘要】 以纳米Li4Ti5O 12正极材料为研究对象,采用恒电位间歇滴定法(P ITT)测定固相材料Li4Ti5O 12中Li+的扩散速率,解析Li+在纳米Li4Ti5O 12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10-12~10-10cm 2/s数量级,主要集中在10-11 cm 2/s附近。嵌锂过程中,D Li+先出现极小值,然后出现极大值;脱锂过程中,D Li+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。更多还原

【Abstract】 Nanostructured Li4Ti5O12 was used as a cathode material for the study. The chemical diffusion coefficient of Li-ion in Li4Ti5O12 was measured by potentiostatic intermittent titration technique(PITT) method and Li+diffusion behavior in nano Li4Ti5O12 was analyzed during the process of charging and discharging. The result shows that the diffusion coefficient of lithium ion in active material ranges from 10-12to 10-10cm2/s, and mainly concentrates in10-11cm2/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.更多还原