摘要
20Ah锂离子动力电池在室温条件下不同倍率的循环性能测试表明,经过2C,3C高倍率循环200周之后的电池容量衰减率为25.58%和34.85%,而经过1C循环200周的电池衰减仅为20.28%。经过3C循环200周的电池内阻在完全放电态时相对于新电池增加了32.9%。通过对半电池的研究,发现高倍率条件下,负极引起的容量损失占主要地位,通过进一步交流阻抗的研究,得出在高倍率条件下负极SEI膜增厚,导致Li+在负极表面脱嵌阻力增大是引起电池衰减的主要原因。
Capacity fade of 20 Ah power Li-ion batteries cycled by using different discharge rates was studied at ambient temperature. The capacity losses were estimated after 200 cycles at 2C and 3C discharges rates and were found to be 25.28 % and 34.85 % of the initial capacity, respectively. At 1 C discharge rate the capacity lost was only 20.28 %. The cell cycled at high discharge rate （3C） showed that the largest internal resistance increased of 32.9 % relatively to the resistance of the fresh cells. Half-cell study indicated carbon loss after cycles dominated the capacity fade of the whole cell at high discharge rates, the main reason of capacity fading at high discharge rates was the thickness increase of anode SEI film, which induced resistance enhancement of Li^＋ deintercalation on the surface of anode by EIS testing.
出处
《广州化工》
CAS
2008年第3期1-4,共4页
GuangZhou Chemical Industry
关键词
锂离子动力电池
容量衰减
高倍率放电
power lithium ion batteries
capacity fading
high discharge rates
