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Thermal management is a crucial parameter in lithium-ion batteries to maintain the temperature of the batteries within safer working limits. If the optimum working temperature is not maintained, it triggers thermal runaway conditions and causes them to propagate heat from one cell to another within pack level configurations. In battery thermal packaging, several government norms such as GB 38031/32 has suggested that for optimum thermal packaging, there should be a significant delay in the thermal runaway trigger point which can prevent a vehicle from going into catastrophic failure since the driver gets a preventive alert for the high-rise temperature of a cell at an early stage. Delaying thermal runaway occurrence can be effectively achieved by using an integrated layer of PCM. However, present conventional PCMs have a lower thermal conductivity which poses instability in delaying thermal runaway trigger point. This can be improved by using graphene-enhanced composite phase change material, in which the percentage of added extended graphene (EG) determines the improvement in thermophysical property, concisely thermal conductivity of CPCM. The current study examines thermal runaway in widely used cathode materials, LiNiMnCoO 2 (NMC) and LiFePO 4 (LFP), within a typical large format prismatic cell profile with a commonly used heater-assisted test. The thermal runaway trigger point is monitored for the cases of cell without CPCM and with CPCM to find potential improvement in the delay point. Thermal runaway modeling and statistical safety regime response show that submerging batteries in a CPCM can delay thermal runaway onset by 20 min. When scaling up to a 7S1P battery module level, it is concluded that the smallest addition of EG in CPCM can delay the thermal runaway trigger point and reduce peak temperatures in the battery module over 66 to 113.2 min, which strategically complies with battery safety norms. • The safety regime response of Li-Ion cell is investigated for different cathodic chemistry. • A comprehensive validated four equation battery thermal abuse model is developed. • Thermal behavior of battery with varying composite phase change material thermal conductivity is investigated. • A novel statistical approach is shown to find the most effective TMS parameter. [ABSTRACT FROM AUTHOR]

The introduction of a high-thermal-conductivity porous medium stands as an effective strategy for enhancing the heat transfer rate within battery thermal management using phase change material (PCM). In this study, we have delved into the investigation of heat transfer augmentation in battery thermal management through the implementation of toroidal porous medium. The exploration encompasses the effects of Rayleigh numbers, thicknesses of the toroidal porous medium, different kinds of porous medium and PCM. By comparing the liquid fraction, dynamic temperature and the latent heat ratio, we found the effect of Rayleigh number and thickness of porous medium on the property of the battery thermal management. The results indicate that by applying thicker toroidal porous medium could weaken the heat accumulation derived by high Rayleigh numbers. Case of d = 0.273R exhibits superior performance for a significant portion of the entire process compared to other cases with thickness of 0.235R, 0.326R, 0.408R and uniform distributed, while the dominant position is difficult to hold due to the heat accumulation. The conclusion is universal for different porous medium and PCM materials. The optimal distribution of porous medium should seek a balance between enhancing heat conduction and weakening thermal convection. A more scattered distributed porous medium could weaken the effect of heat convection and rises the latent heat ratio. [ABSTRACT FROM AUTHOR]