锂离子电池组合前后的特性研究

为更好地使用锂离子电池组,更精确地估算电池的荷电状态(SOC),对锂离子电池组合前后进行了常温4.0 A充放电、常温7.5 A放电、-20℃下4.0 A放电以及55℃下4.0 A放电等实验测试。实验结果显示:锂离子电池成组后的充放电特性有所下降,电池组总容量下降为单体电池的90%左右,SOC偏低,工作电压的下降速率在放电末期急剧上升,可达平台区的50倍。对电池组的一致性进行了分析,得出锂离子电池成组时应充分考虑单体电池的一致性;在估算SOC时,采用电池组参数和单体电池参数相结合的方式。

In order to make better use of the Li-ion batteries and estimate the state of charge(SOC) more accurately,some charge-discharge experiments of Li-ion batteries before and after grouped,including 4.0 A charge-discharge at normal temperature,7.5 A discharge at normal temperature,4.0 A discharge at-20 ℃ and 55 ℃ were done.The experiment results showed that the charge-discharge characteristics of the Li-ion batteries descended after grouped,the batteries had lower total capability(about 90% of the single cell),lower SOC,its work voltage descended faster especially at the end of its charge phase(50 times faster than that in 'flat roof' stage).The consistency of the batteries was analyzed. The consistency of the single cell should be taken into account when Li-ion batteries were used in group.As estimating the SOC of the batteries,the parameters of the single cell and the batteries should be combined.

“863”计划电动汽车重大专项车用高性能蓄电池组及其管理模块子项目(2005AA501550)