Anisotropic and homogeneous model of heat transfer for self-heating ignition of large ensembles of lithium-ion batteries during storage

Self-heating ignition is a fire hazard in warehouses when stacking large quantities of reactive materials for storage, including lithium-ion batteries. Due to the heavy costs and dangerous risks, thermal behaviour large-scale LIB ensembles usually studied by numerical methods. The state-of-the-art self-heating models on LIBs are either too computationally expensive be applied predictions ensembles, or capable ensemble but missing important heat transfer characteristics like insulation packaging. Based four-step kinetics from literature (Solid electrolyte interphase decomposition, negative-electrolyte reaction, positive-electrolyte decomposition), we have developed 3D anisotropic homogeneous (Ani-Hom) transient model that can incorporate complex packaging numerically affordable based COMSOL Multiphysics. effect considered using weight-averaged thermophysical properties directional conductivities. Lithium Cobalt batteries (LCO) used as case study. This Ani-Hom was verified comparing box-scale simulation against an isotropic heterogeneous (Iso-Het) literature. Both temperature evolution generation agreed within 5%, while computational time one order magnitude lower than Iso-Het model. then four possible storage sizes, ranging single cell rack with around 10 million cells, different packing configurations spacing between cells. predicts presence promotes ignition. A this LCO predicted self-ignite at ambient 45?, which indicates warehouse vulnerable hazards warm environments. defects abuse will even critical temperature. work provides insights into effects during contributes better understanding help mitigate such fires.