The safety concern of lithium-ion batteries has been in the fore-front since its commercialization. Lithium-ion batteries (LIB) have been widely used as types of cylinder (e.g., 18650 LIB) and prismatic Li-ion batteries. The 18650 LIB uses liquid organic electrolytes with higher instability than the LIPB, which contains gel/solid polymer electrolytes. To improve the thermal stability of LIPB at elevated temperatures, the thermal runaway mechanisms should be identified. The present research takes a green approach by applying adiabatic calorimetry experiments to evaluate the thermal runaway profiles, along with the thermokinetic parameters for the LIPB at various states of charge (SOC). Calorimetry data from various 18650 LIB and LIPB with different SOC were simulated using thermally analytical methods to calculate the thermal explosion energies and electrochemical kinetics. A novel self-heating model was also created based on a pseudo-zero-order and pseudo-first-order reaction for 18650 LIB and LIPB, respectively. The Arrhenius equation was proposed for studying the exothermic reaction of a charged battery. LIB and LIPB were found to be equivalent to 1.86 and 0.028 g of trinitrotoluene (TNT) in case of explosiveness. With a limited overpressure value of 0.3 psig, the safety distance of LIB in the ambient air environment was 5.79 m and the safety distance of LIPB in the ambient air environment and nitrogen atmosphere was 1.32 and 1.66 m, respectively. The pressure increased from 9.77 to 43.86 psig within 0.2 m when SOC of LIB rose from 30 to 100%. The results indicated that the higher pressure, the more prominent was the effect range. With the same distance, the explosion pressure of LIPB in the nitrogen atmosphere was 43% higher than in the ambient air environment, which was interpreted as that nitrogen is beyond restraint in the LIPB explosion reaction.
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