دانلود رایگان مقاله مدل محاسباتی یکپارچه موضوع باتری لیتیوم-یون به نفوذ میخ

Abstract

The nail penetration of lithium-ion batteries (LIBs) has become a standard battery safety evaluation method to mimic the potential penetration of a foreign object into LIB, which can lead to internal short circuit with catastrophic consequences, such as thermal runaway, fire, and explosion. To provide a safe, time-efficient, and cost-effective method for studying the nail penetration problem, an integrated computational method that considers the mechanical, electrochemical, and thermal behaviors of the jellyroll was developed using a coupled 3D mechanical model, a 1D battery model, and a short circuit model. The integrated model, along with the sub-models, was validated to agree reasonably well with experimental test data. In addition, a comprehensive quantitative analysis of governing factors, e.g., shapes, sizes, and displacements of nails, states of charge, and penetration speeds, was conducted. The proposed computational framework for LIB nail penetration was first introduced. This framework can provide an accurate prediction of the time history profile of battery voltage, temperature, and mechanical behavior. The factors that affected the behavior of the jellyroll under nail penetration were discussed systematically. Results provide a solid foundation for future in-depth studies on LIB nail penetration mechanisms and safety design.

5. Concluding

remarks Short circuit caused by nail penetration is an important issue in LIB safety. This study established an integrated mechanical–electro chemical–thermal behavior computation model by combining three models, namely, a 1D battery model, a 3D failure model, and a coupled short circuit model. The 1D battery model was modified based on the Newman model and used to calculate the electrochemical behavior of the jellyroll. The 3D failure model, which used a homogeneous model with external component layers, indicated internal short circuit displacement caused by the failure of the separator. Lastly, the coupled short circuit model was used to calculate electrochemical and thermal behaviors following an internal short circuit. These three models were validated separately, and the integrated model was also verified via experiments. A series of parametric studies on various nail sizes, shapes, SOC values, penetration speeds, and nail tip displacements was conducted using the established integrated model. The following important results of the parametric studies were obtained for 18650 LIB.
For different nail shapes, the order of the capability to deform the jellyroll is cone > sphere > ellipsoid > flat. The order of short circuit displacement is sphere > cone > flat > ellipsoid. The order of increasing temperature rate is sphere < cone < flat < ellipsoid.
For penetration nail sizes, short circuit displacement and needle radial exhibited the linear relationship of dfl ¼ 3:3Rnl. The extreme value of the stable current was achieved when Rnl ¼ 0:202dpn.
For different SOCs, short circuit displacement presented a linear relationship with SOC, i.e., dfl = 3.12  0.7SOC. For the jellyroll with a higher SOC, the current increasing rate and the stable current were slightly higher, and the stable current lasted longer.