Numerical investigation of thermal runaway behavior of lithium-ion batteries with different battery materials and heating conditions

The proliferating thermal runaway accidents are still the main obstacle that hinders the extensive applications of lithium-ion batteries. An abuse condition triggering thermal runaway of particular interest is local heating, which is the direct and common cause. However, a comprehensive simulation and analysis of thermal runaway under local heating from the perspective of heat generation, external heat and heat loss still lacks. In this study, a three-dimensional model was developed within frame of open source computational fluid dynamics code OpenFOAM to study the effects of various battery materials, external heating conditions and heat dissipation conditions on battery thermal runaway behavior. The results indicate that batteries with Li4Ti5O12 anode and LiFePO4 cathode show better thermal safety and stability than other materials. The increasing separator melting temperature improves the onset temperature of thermal runaway and delays its occurrence. Additionally, the heating position near the bottom of batteries was found more inclined to induce thermal runaway than other heating positions. Increasing air velocity and reducing ambient temperature help batteries stay in the steady-state and provide effective relief from thermal runaway. These conclusions may provide references for the safe design of thermal management system of battery packs