锂离子电池脉冲充电策略研究及表征分析

Research and characterization of pulse charging strategy for lithium-ion traction battery

动力电池充电策略对提高电动汽车性能和使用寿命起着至关重要的作用。针对一种三元材料体系18650圆柱形电池进行脉冲充电策略研究,将其与标准恒流恒压充电策略进行综合比对,全面客观地分析脉冲充电策略关键参数对动力电池电性能的影响,并系统地评估了脉冲充电策略对电池寿命的影响。在循环寿命研究方面,采用电化学交流阻抗欧谱(EIS)分析不同循环周数和SOC下的交流阻抗,采用X射线断层扫描(CT)无损分析技术对循环500周后电池结构进行表征分析,揭示了带负脉冲充电策略对电池循环性能和结构影响的关系。

Charging strategies of traction battery play a crucial role in improving the performance and life of electric vehicles.In this paper,the pulse charging strategy for a ternary material system 18650 cylindrical battery is studied,and it is compared with the standard constant current and constant voltage charging strategy.The impact of the key parameters of the pulse charging strategy on the electrical performance is comprehensively and objectively analyzed.The impact of the pulse charging strategy on battery life was systematically evaluated.In the aspect of cycle life research,electrochemical Impedance Spectroscopy(EIS)was used to analyze the AC impedance under different cycles and SOC,and the cell structure was characterized by X-ray tomography(CT)non-destructive analysis.The relationship between the pulse charging strategy and the cycle performance and structure of the battery is revealed.