A novel fast capacity estimation method based on current curves of parallel-connected cells for retired lithium-ion batteries in second-use applications
A novel fast capacity estimation method based on current curves of parallel-connected cells for retired lithium-ion batteries in second-use applications
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DOI：
10.1016/j.jpowsour.2020.227901
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发表时间：
2020-05
影响因子：
9.2
通讯作者：
Long Chang;Chunyu Wang;Chenghui Zhang;Lin-jing Xiao;N. Cui;Hongyu Li;Jianfeng Qiu
中科院分区：
文献类型：
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作者：
Long Chang;Chunyu Wang;Chenghui Zhang;Lin-jing Xiao;N. Cui;Hongyu Li;Jianfeng Qiu
电动汽车中退役的锂离子电池在二次利用应用中，特别是在储能方面，提供了相当大的社会、经济和环境效益。然而，有效容量的估算是实现大规模退役电池二次寿命的关键技术和难点。针对这一问题，本文从并联电池内部电流分布的新角度出发，提出了一种新的快速容量估计方法。首先，利用并联电池分析模型，推导出电容与电流分布之间的关系。根据关联关系，只需测量一个完整放电循环的电流曲线，即可同时估算出各电池并联后的容量，比一个接一个效率更高。并设计了实验装置和实验程序对该方法进行了验证。结果表明，该方法是可行和准确的。同时，通过对三种不同类型电池的测量结果进行比较，找出了影响测量精度的主要因素包括开路电压、电池参数和负载参数的差异。不同方法的比较表明，该方法具有效率高、计算量小、累积误差小、荷电状态一致性好等优点，有利于退役电池的重组，促进二次电池的应用。
Retired lithium-ion batteries from electric vehicles provide considerable social, economic and environmental benefits in second-use applications especially for energy storage. However, the effective capacity estimation is a key technique and difficulty for second-life of large-scale retired cells. To address the issue, this paper provides a fast novel capacity estimation method from a new perspective of current distribution within parallel-connected cells. Firstly, using the parallel-connected cells analytical model, the correlation between capacity and current distribution is deduced. According to the correlation, the capacity of each cell is simultaneously estimated for thenparallel-connected cells by measured the current curves in only one complete discharge cycle, which is more efficient than one after another. Then an experimental device and procedure are designed to verify the method. Results demonstrate that the method is feasible and accurate. Meanwhile, through comparing the results of packs with three different battery types, the main factors affecting accuracy are found including open circuit voltage, parameter difference of cell and loads. Finally, comparison of different methods shows that the method has the advantages of high efficiency, low calculation, low accumulative errors and good consistency of state-of-charge, which is helpful for regrouping of retired cells and promoting second-life battery applications.