In situ Raman investigation on gas components and explosion risk of thermal runaway emission from lithium-ion battery

Abstract

The gas emission of lithium-ion battery thermal runaway (LIB-TR) is of great significance for the early warning and safety assessment of TR. A Raman spectroscopy methodology for in-situ real-time measurement of LIB-TR gas composition and explosion risk was proposed in this paper. The TR gas released by commercial 18,650 LIBs during external heating abuse was used to study its compositions at different states of charge (SOC) and atmosphere. The lower explosive limit (LEL), upper explosive limit (UEL) and explosive limit range (ELR) were calculated based on the gas composition detection results of Raman spectrum. The results show that Raman spectroscopy can detect organic solvent vapor (OSV) immediately when the safety valve is opened. When the TR occurs, the proportion of CO, CO2, H2, CH4, C2H4, and C3H6 increases rapidly. SOC and atmosphere directly affect the explosion characteristics of TR gas. In air atmosphere, LEL, UEL and ELR increase with the increase of SOC, and the explosion risk of TR gas in nitrogen atmosphere is lower than that in air atmosphere. The results reveal that Raman spectroscopy presents a promising tool for the early detection of LIB-TR and the explosion risk assessment of TR gas.