汽车工程 ›› 2022, Vol. 44 ›› Issue (5): 722-729.doi: 10.19562/j.chinasae.qcgc.2022.05.009

所属专题: 新能源汽车技术-动力电池&燃料电池2022年

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基于梁单元简化模型的锂电池组碰撞安全临界条件的判定

陈光,魏晨阳,李晓宇(),景国玺   

  1. 1.河北工业大学,天津市新能源汽车传动与安全技术重点实验室,天津  300130
    2.河北工业大学机械工程学院,天津  300401
  • 收稿日期:2021-10-09 修回日期:2021-11-03 出版日期:2022-05-25 发布日期:2022-05-27
  • 通讯作者: 李晓宇 E-mail:lixiaoyu@hebut.edu.cn
  • 基金资助:
    河北省自然科学基金(E2019202201)

Judgment of Critical Condition for Crash Safety of Lithium Battery Pack Based on Simplified Beam Element Model

Guang Chen,Chenyang Wei,Xiaoyu Li(),Guoxi Jing   

  1. 1.Hebei University of Technology,Tianjin Key Laboratory of Power Transmission and Safety Technology for New Energy Vehicles,Tianjin  300130
    2.School of Mechanical Engineering,Hebei University of Technology,Tianjin  300401
  • Received:2021-10-09 Revised:2021-11-03 Online:2022-05-25 Published:2022-05-27
  • Contact: Xiaoyu Li E-mail:lixiaoyu@hebut.edu.cn

摘要:

针对现有电池单体有限元模型单元数量多、计算速度慢、在整车碰撞分析难以应用的问题,提出一种采用梁单元,反映电池单体壳体的压溃和弯曲特性的有限元模型。通过对比电池单体的轴向压溃、径向挤压和压痕试验结果,验证了建立的电池单体简化模型的有效性。应用该简化模型进行了6×4电池组撞击刚性墙和刚性墙撞击电池组两种工况的仿真,并根据电池单体短路失效临界应变,确定电池发生短路失效的临界撞击速度和撞击质量。结果表明,在电池组撞击刚性墙工况中,撞击速度为245 km/h时,靠近刚性墙第2和第3层电池单体最先失效;而在刚性墙撞击电池组工况中,撞击质量为16.06 kg时,最先失效的电池单体位于靠近刚性墙的第2层。因此,应依据不同的工况来确定电池组内首先失效单体的位置。

关键词: 18650锂电池, 梁单元, 简化模型, 冲击, 临界条件

Abstract:

In view of the difficulty in applying the existing battery cell finite element model to vehicle crash analysis due to its large number of elements and low speed of calculation, a beam-element-based finite element model, reflecting the crushing and bending characteristics of cell housing is established. The effectiveness of the simplified model for battery cell is verified by comparing the results of axial crushing, radial squishing and indenting tests of battery cell. Simulations are conducted on the proposed simplified model of battery pack with 6 x 4 cells under two conditions: battery pack impacting rigid wall and rigid wall (steel plate in fact) impacting battery pack to determine the critical impact speed and critical mass of impactor leading to deformation and short-circuit failure of battery. The results show that in the condition of battery pack impacting rigid wall, the second and third rows of battery pack near rigid wall begin to fail when the impact speed reaches 245 km/h; while in the condition of rigid wall impacting battery pack, the cell starting to fail when the mass of impator larger than 16.06 kg is in the second row of battery pack near impactor. Therefore, the position of the battery cell first failing should be determined according to different impact conditions.

Key words: 18650 lithium battery, beam elements, simplified model, impact, critical conditions