Effect of EMC vapor on explosion characteristics of thermal runaway products of lithium-ion batteries

doi:10.16265/j.cnki.issn1003-3033.2026.09.0044

Abstract

Abstract:

To clarify the mixed explosion characteristics of high-temperature electrolyte vapor and thermal runaway gases from lithium-ion batteries, and to reveal the effect of such vapor on the explosion hazard of battery thermal runaway products, we conducted systematic tests in a 20 L spherical apparatus on gas mixtures of different state of charge (SOC) batteries and EMC vapor, combined with computational fluid dynamics (CFD) simulation and chemical kinetics analysis to deeply examine the explosion evolution behavior. The findings reveal that high temperature exerts both a physical dilution effect and a chemical kinetic enhancement effect. Thermodynamically, the high-calorific EMC vapor combined with 100% SOC gas results in significant energy superposition, leading to the highest maximum explosion pressure. Kinetically, oxygen-containing radicals generated by the thermal decomposition of EMC at high temperatures accelerate the core chain-branching reactions, causing the maximum rate of pressure rise for low-SOC gases to increase by over 240%. Moreover, the acceleration of microscopic reactions further induces macroscopic flow instability, forming a physico-chemical coupling mechanism.

Key words: ethyl methyl carbonate (EMC), electrolyte vapor, lithium-ion battery, thermal runaway, explosion characteristics, high temperature

CLC Number:

X932爆炸安全与防火、防爆

Zhang Ying, Peng Zicong, Li Qi, Zhang Churan, Han Jinghao, Chen Yue. Effect of EMC vapor on explosion characteristics of thermal runaway products of lithium-ion batteries[J]. China Safety Science Journal, 2026, 36(9): 26-34.

Figures/Tables 8

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气体组分	50% SOC	75% SOC	100% SOC	115% SOC
H₂	20.8	21.8	29.4	34.0
CO	4.8	6.4	9.1	6.4
CH₄	1.6	1.9	5.4	2.6
C₂H₄	6.6	6.3	7.2	4.7
CO₂	66.2	62.6	48.3	52.2

系列	t/℃	SOC/ %	r (n_E/ n_g)	控制方式	初始压力 P/kPa	总气体物质的量n/mol
A	20	50, 75, 100, 115	0 (纯气体)	定压	101.3	0.84
	110	50, 75, 100, 115	0 (纯气体)	定压	101.3	0.64
	110	50, 75, 100, 115	0 (纯气体)	定量	132.6	0.84
B	110	50, 100	1∶5, 1∶4, 1∶3	定压	101.3	0.64
C	110	—	∞ (纯EMC)	定压	101.3	0.64