锂离子电池低温放电性能及电池间一致性(英文)  

Lithium-ion battery discharge behaviors at low temperatures and cell-to-cell uniformity

作　　者：张剑波[1] 黄俊[1] 陈璐凡 李哲[1] 

机构地区：[1]清华大学汽车安全与节能国家重点实验室

出　　处：《汽车安全与节能学报》2014年第4期391-400,共10页Journal of Automotive Safety and Energy

基　　金：国家自然科学基金资助项目(51207080,51377097)

摘　　要：用实验方法研究了锂离子电池在低温下的放电性能以及电池间一致性。在不同温度下,测量了多节18650型号的锂离子电池的恒流放电与电化学阻抗谱(EIS)。当环境温度从25℃降至-20℃时,4节电池的平均容量降低了58.4%,而容量的标准方差增大了6倍。EIS结果表明:降低环境温度会明显增大电池的阻抗,特别是电荷转移阻抗(RCT),同时,电池间的阻抗差异也被放大。15节电池的统计结果表明:电池放电容量与其阻抗之间存在线性关系。因此,低温下电池容量方差的增大是由于电池阻抗方差的增大引起的,而其中,电荷转移阻抗(RCT)起了主要作用。The discharge behavior and uniformity of lithium-ion batteries were experimentaly investigated at low temperatures. The discharge test and electrochemical impedance spectroscopy （EIS） test were conducted for several commercial 18650 type cels. The cel average capacity decreases by 58.4% with the capacity standard deviation increasing by 6.6 times when the temperature decreases from 25℃ to-20℃. The charge transfer resistance （Rct） dramaticaly increases, dominating other types of resistance. The cel impedance variations, mainly in the Rct, increase signiifcantly at lower temperatures. A linear correlation between the capacity and the over-potential resistance is established by statistics from 15 cels. Therefore, at low temperatures, the cel-to-cel capacity variation increase is attributed to the cel over-potential resistance （mainly the Rct） variation increase.

关 键 词：锂离子电池 电池一致性 低温放电性能 电化学阻抗谱 电池分选方法 

分 类 号：TM911[电气工程—电力电子与电力传动]