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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...

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Composite electrode lithium-ion batteries can of fer improved energy and power density, as well as increased cycle life compared to batteries with a single active material electrode. Both available power and cell life are functions of the local current allocated to each composite material, however there are no examples in literature of electrochemical-based models of composite electrode cells that are suitable for estima tion and control. We present a reduced order, electrochemical model of a composite LiMn204 -LiNil / 3Mnl / 3Col / 302 cell that predicts bulk and surface concentrations of each composite material, as well as the local current allocated to each material. Observability properties are analyzed by approximating the system as linear over certain operating conditions. A solution method is developed to use the model in an extended Kalman filter for online state of charge estimation, which is validated with experimental data.

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