Thermal Runaway Propagation Analytics and Crosstalk in Lithium‐Ion Battery Modules

Abstract

The thermal safety of lithium‐ion (Li‐ion) batteries continues to remain a critical concern for widespread vehicle electrification. Under abuse scenarios, thermal runaway (TR) of individual energy‐dense Li‐ion cells can be dominated by various exothermic mechanisms due to interelectrode crosstalk, resulting in an enormous heat generation response that can potentially lead to thermal runaway propagation (TRP) in a battery module. Herein, a hierarchical TRP analytics approach is developed, which includes cell‐level thermokinetic and electrode crosstalk interactions derived from accelerating rate calorimetry characteristics of a representative high‐energy 18650 cylindrical Li‐ion cell with Ni‐rich cathodes and Si–C anodes. The hierarchical TRP model, coupled with multimodal heat dissipation, demonstrated for an exemplar energy‐dense Li‐ion battery module configuration, determines TRP criticality at module level for a wide range of conditions, including ambient temperature, intercell spacing, trigger cell location, external heating power, and heat dissipation coefficients. Potential propagation pathways have been identified, and their underlying attributes in terms of propagation speed, heat release from exothermic reactions, critical thermal energy input, and heat dissipation to surroundings have been quantified. This hierarchical approach, including thermal transfer and chemical interelectrode crosstalk during TR, can provide high‐resolution TRP analytics for energy‐dense Li‐ion battery modules and is scalable to packs.