汽车工程 ›› 2024, Vol. 46 ›› Issue (7): 1157-1166.doi: 10.19562/j.chinasae.qcgc.2024.07.003

• • 上一篇    

软包锂离子电池用铝塑膜成形性能研究

邓道林()   

  1. 宁德新能源科技有限公司研究院,宁德 352000
  • 收稿日期:2024-02-07 出版日期:2024-07-25 发布日期:2024-07-22
  • 通讯作者: 邓道林 E-mail:DengDL@atlbattery.com

Study on Forming Performance of Aluminum-Plastic Film for Pouch Lithium-Ion Batteries

Daolin Deng()   

  1. Research Institute,Ningde Amperex Technology Limited,Ningde  352000
  • Received:2024-02-07 Online:2024-07-25 Published:2024-07-22
  • Contact: Daolin Deng E-mail:DengDL@atlbattery.com

摘要:

为保证软包锂离子电池用铝塑膜封装的可靠性,须严格控制成形后的铝层厚度,而其获得依赖大量的实物试验,导致前期设计优化和后期生产过程质量监控均须耗费高额成本。本文采用实物试验和仿真模拟相结合的方法,构建能精准表征铝塑膜力学性能的本构方程,并提出基于整体铝塑膜厚度对铝层厚度的预测方法,实现成形后铝塑膜和铝层厚度的精准预测。同时,基于仿真DOE,筛选关键影响因子,构建响应曲面模型,实现不同产品的快速预测及最佳参数匹配设计,也为生产实时质量监控提供解决方案。研究结果表明,多层复合铝塑膜在塑性阶段表现出了明显的各向异性,3参数Barlat-Lian本构模型,可较好表征铝塑膜的各向异性性能,明显优于单一方向弹塑性模型,可实现铝塑膜成形性能的精准预测。所构建的响应曲面模型可替代精细化有限元模型,实现对铝塑膜和铝层厚度精准预测和参数优化,误差小于5%,工艺参数优化后冲压成形铝层厚度可提升10%~20%。集成开发的应用APP可满足冲压工艺参数的快速设计评估、优化及成形质量实时监控等应用需求。

关键词: 锂电池, 铝塑膜, 冲压成形, 各向异性, 响应曲面, 预测及优化

Abstract:

To ensure the reliability of aluminum-plastic film encapsulation for lithium-ion batteries, strict control of the aluminum layer thickness after forming is necessary. However, obtaining the thickness relies heavily on physical experiments, resulting in high cost for both early design optimization and later production process quality monitoring. In this paper, a combination of physical experiments and simulation modeling is adopted to establish a constitutive equation that can well characterize the mechanical properties of the pouch during forming. Additionally, a prediction method for the aluminum layer thickness based on the overall aluminum-plastic film thickness is proposed, enabling precise prediction of the aluminum-plastic film and aluminum layer thickness after forming. Furthermore, based on simulation Design of Experiments (DOE), key influencing factors are screened to construct a response surface model, facilitating rapid prediction and optimal parameter matching design for different products, which also provides a solution for online monitoring of forming quality during production. The results show that the multi-layer composite aluminum-plastic film exhibits obvious anisotropy during the plastic stage. The 3-parameters Barlat-Lian constitutive model effectively represents the anisotropic properties of the film, and outperforms the single-directional elastic-plastic model, achieving accurate prediction of the aluminum-plastic film performance after forming. The constructed response surface model can replace the refined finite element model, and have excellent prediction accuracy for the thickness of the composite aluminum-plastic film and the aluminum layer, with an error less than 5%. By optimizing the process parameters, the formed thickness of the aluminum layer can be increased by 10%~20%. The integrated development application APP can meet the requirements for quick design evaluation, parameters optimization, and online monitoring of the forming quality.

Key words: lithium-ion batteries, aluminum-plastic film, pouch forming, anisotropy, response surface, prediction and optimization