Investigation of the mechanical response and modeling of prismatic lithium-ion batteries upon abusive loading

Abstract

The integrity and safety of lithium-ion batteries (LIBs) under mechanical stress are paramount for ensuring the reliability of electric vehicles. Particularly, extrusion deformation poses a significant risk as a primary contributor to the failure of LIBs. This research comprehensively examines the dynamic responses of prismatic LIBs (PLIBs) under varying conditions, including different orientations, states of charge (SOC), and states of health (SOH). We employed quasi-static compression and indentation tests to explore these aspects. Subsequently, we developed a sophisticated homogenized finite element model that encapsulates anisotropy, SOC, and SOH, grounded in empirical data. Upon rigorous validation, this model was utilized to dissect the dynamic mechanical behavior of LIBs under complex loading scenarios. In previous research, finite element models have primarily focused on examining the mechanical responses of lithium-ion batteries under the influence of SOC and strain rate, with particular emphasis on cylindrical and pouch cell types, while prismatic cells have received comparatively less attention. Moreover, our model incorporates the effects of both SOC and SOH in a more streamlined manner, without the need for complex electrochemical modeling, while maintaining simulation accuracy within acceptable error margins. Our findings reveal that both SOC and SOH markedly affect the load capacity of PLIBs, exhibiting a positive correlation with this capacity. Results are instrumental in delineating the deformation response characteristics of PLIBs under mechanical loading, offering valuable insights for the safety design of square PLIBs in practical engineering applications.