最大可用容量和内阻实现锂离子电池快速筛选

Rapid screening of lithium ion battery by maximum available capacity and internal resistance

针对目前锂离子电池初筛选方法存在耗时久、计算量大等问题,提出了一种快速获取电池最大可用容量和欧姆内阻的方法。通过该方法获取欧姆内阻:建立电池一阶RC等效电路模型;对电池进行一次动态工况放电实验;利用带遗忘因子的递推最小二乘法辨识模型欧姆内阻。最大可用容量是利用动态工况放电前后电量阶跃值和电池荷电状态(S OC)差值关系估算获得。通过实验测试验证了所提出方法 ,最大可用容量估算误差不超过1.3%,欧姆内阻估算误差不超过3%。将该方法用于电池筛选中,实验结果表明筛选时间相比传统筛选方法缩短了三分之一。该研究对锂电池初筛选有一定的实用价值。

Aiming at the problems of long time consuming and high computational cost in the early screening of Li-ion battery,a method to obtain the maximum available capacity and ohmic resistance of the battery is proposed.Firstly,the first-order RC equivalent circuit model of the battery is established.Secondly,a dynamic discharge experiment is performed on the battery.Finally,the ohms internal resistance is identified by recursive least square method with forgetting factor.The capacity estimated by the relationship between the variable of state of charge(SOC)and electric after the dynamic condition discharge.The experimental results show that the estimated error of the maximum available capacity is less than 1.3%and the error of ohmic resistance is less than 3%.The results show that the screening time is shortened by one third compared with the traditional screening method.This research has certain practical value to the lithiumbattery initial screening.