锂离子蓄电池相关特性试验研究

Study of lithium battery's characteristics by tests

为了确定锂离子蓄电池在不同负荷下的最小允许放电电压、内阻变化规律以及内阻消耗量,对4节3.2 V/60 Ah的锂离子蓄电池单体串联组成电池组进行了放电试验,记录不同时刻蓄电池组端电压、放电电流和内阻值,利用M atlab对所采集到的数据进行处理,计算出了各种不同负载条件下蓄电池组的放电量、负载消耗的能量、蓄电池内阻消耗的能量以及蓄电池的内阻消耗的能量占整个能量消耗的百分比,并绘制出蓄电池试验变化曲线。结果表明:锂离子蓄电池单体所允许的放电端电压最小值在2.75 V左右,内阻值约为0.75 mΩ,不随放电量和负载的变化而发生变化;在负载相同的条件下,电池组放电电流减小趋势和端电压下降趋势一致;负载越大内阻消耗量也越大。以上结论为蓄电池能量管理系统开发提供理论依据。

To make certain the lithium battery＇s terminal limited discharge voltage and internal resistance in different currents,four 3.2 V/60 Ah lithium batteries were connected in series to form battery pack for tests.The lithium battery pack terminal voltage,current and overall internal resistance were recorded with the time change.By analyzing data from the tests with Matlab,the lithium battery pack capacity,and energy consumed by the load and internal resistance were figured out,and the lithium battery pack t-U,t-I,t-△U/△t and t-r graphs were drawn.From the figures,it is concluded that the limited discharge voltage of a single lithium battery is about 2.75 V,the internal resistance of a single lithium battery is about 0.75 mW,the lithium battery pack current and the voltage change trend is the same when the load keeps changeless,the higher load the less capacity that lithium battery pack can release,the energy consumed by internal resistance to the energy that lithium battery release is higher as the load increase.All the above conclusions provide a basis to the development of battery management system.