A Simulation Framework for Battery Cell Impact Safety Modeling Using LS-DYNA

Abstract

The development process of electrified vehicles can benefit significantly from computer-aided engineering tools that predict the multiphysics response of batteries during abusive events. A coupled structural, electrical, electrochemical, and thermal model framework has been developed within the commercially available LS-DYNA software. The finite element model leverages a three-dimensional mesh structure that fully resolves the unit cell components. The mechanical solver predicts the distributed stress and strain response with failure thresholds leading to the onset of an internal short circuit. In this implementation, an arbitrary compressive strain criterion is applied locally to each unit cell. A spatially distributed equivalent circuit model provides an empirical representation of the electrochemical response with minimal computational complexity. The thermal model provides state information to index the electrical model parameters, while simultaneously accepting irreversible and reversible sources of heat generation. The spatially distributed models of the electrical and thermal dynamics allow for the localization of current density and corresponding temperature response. The ability to predict the distributed thermal response of the cell as its stored energy is completely discharged through the short circuit enables an engineering safety assessment. A parametric analysis of an exemplary model is used to demonstrate the simulation capabilities. Increased utilization of lithium-ion (Li-ion) batteries for a variety of applications is driving the need for advanced simulation tools that can predict the combined structural, electrical, electrochemical, and thermal response to abuse conditions. If such simulation tools are integrated into the product development process, the resultant data have the potential to create highly optimized designs and achieve virtual verification of those designs.In support of automotive durability and crash safety requirements, several experimental and modeling studies have reported analysis of battery mechanical properties and onset of short circuits for various loading conditions. Cylindrical cells have been subjected to uniform radial compression, localized indentation, and bending loads. [1][2][3] Pouch cells have also been subjected to uniform and localized compression loads, 4-8 as well as combined torsion and compression loads 7,9,10 and nail penetration. 11 Many of these references propose mechanical models that achieve reliable agreement between the simulated and measured indenter force and displacement. However, they employ homogenized models for the cell jelly roll aimed at a binary determination of whether a short circuit occurs, and they do not attempt to simulate the multi-physics consequences following the onset of short circuits.Multi-physics models for battery abuse response prediction have been proposed for nail penetration, 12 the short-time response to crush, 13 and general high-rate discharge pertaining to external short circuits 14 without mechanical loading or a...

Review: Characterization and Modeling of the Mechanical Properties of Lithium-Ion Batteries

“…Marcicki et al developed a coupled structural-electrochemical-thermal model in LS Dyna to simulate the response of pouch cells under spherical and cylindrical impact loading [68]. Tensile tests in different directions as well as compression tests were conducted on the separator and electrodes to determine their material properties and FE models were developed to validate the models.…”

Dynamic Mechanical Compression Impulse of Lithium-Ion Pouch Cells

“…In a review of mechanical modelling of lithium-ion batteries, Zhu identified aspects of mechanical behaviour inherent to lithium-ion cells that should be represented by accurate homogenized material models that included [10]: the pressure dependence of the compression stiffness of porous layers, the poromechanics of the electrolyte-filled porous structure of the jellyroll, anisotropy of individual layers, plasticity, and crack propagation. Despite the complexity of multi-physics in the jellyroll [11][12][13], a notable consensus has arisen within a growing body of research that structural properties can be adequately approximated in solid mechanical terms for the practical finite element simulation of lithium-ion cells [6,[14][15][16][17][18][19]. Due to the common motivation of simulating automotive crash events, research has been predominantly concerned with bending and compression deformation.…”

“…Poisson's ratio [20] and has been likened to the behaviour of cellular materials [21]. To this purpose, crushable foam and honeycomb material models have been frequently employed for homogenization techniques in commercial finite element codes such as LS DYNA and Abaqus [4,15,18,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. The stiffness of polymeric foams is strain-rate dependent and is generally characterized by three phases of compression [37][38][39][40].…”

Study on the failure behavior of the current interrupt device of lithium‐ion battery considering the effect of creep

“…Marcicki and Zhu 18 used a combination of material testing and finite element simulation of components to study the thermal runaway phenomenon of a power battery during a sudden external short circuit. The finite element model could predict the distributed thermal response of the battery in an external short circuit.…”