TY - JOUR
T1 - On flammability limits of battery vent gas
T2 - Role of diffusion, radiation and chemical kinetics
AU - Yu, Ruiguang
AU - Liu, Jie
AU - Liang, Wenkai
AU - Law, Chung K.
AU - Wang, Hewu
AU - Ouyang, Minggao
N1 - Funding Information:
This study is supported by the National Natural Science Foundation of China (NO. 52076011 ) and the Strategic Science and Technology Innovation Cooperation of China (NO. 2022YFE0207900 ).
Publisher Copyright:
© 2023 The Combustion Institute
PY - 2023/3
Y1 - 2023/3
N2 - An experimental and computational investigation has been conducted on the determination of the flammability limits of the multi-component NCA (Nickel, Cobalt, and aluminum) battery vent gas (BVG) blended with an inert gas (CO2, H2O, and N2), and on the understanding of associated limit phenomena in general. The simulation results based on detailed chemical kinetics and transport properties agree well with the experimental data from low to high inert gas ratios for both lean and rich limits. In addition, when the inert gas ratio is very high, an absolute limit state exists, at which the lean and rich limits merge, and beyond which flame propagation is not possible. The combustible regime increases in the order of CO2, H2O and N2. The effects of each inert gas on the flame temperature, laminar flame speed, flame broadening, diffusion and radiation are identified and investigated. Furthermore, a linear growth law of the normalized sensitivity with the dominant chain termination reaction rate to the chain branching reaction rate was found near the lean flammability limit. Based on first principle concept of competition between the dominant chain branching and termination reactions, the criterion of a unified flammability exponent is extended to the current multi-component mixture system. This outcome yields useful insight into the fundamental processes of flammability limits, and scrutinizes the heat loss and chain termination effects of flammability limits. Results of this study provide guidance for hazard mitigation and fire suppression for the thermal runaway of lithium-ion batteries.
AB - An experimental and computational investigation has been conducted on the determination of the flammability limits of the multi-component NCA (Nickel, Cobalt, and aluminum) battery vent gas (BVG) blended with an inert gas (CO2, H2O, and N2), and on the understanding of associated limit phenomena in general. The simulation results based on detailed chemical kinetics and transport properties agree well with the experimental data from low to high inert gas ratios for both lean and rich limits. In addition, when the inert gas ratio is very high, an absolute limit state exists, at which the lean and rich limits merge, and beyond which flame propagation is not possible. The combustible regime increases in the order of CO2, H2O and N2. The effects of each inert gas on the flame temperature, laminar flame speed, flame broadening, diffusion and radiation are identified and investigated. Furthermore, a linear growth law of the normalized sensitivity with the dominant chain termination reaction rate to the chain branching reaction rate was found near the lean flammability limit. Based on first principle concept of competition between the dominant chain branching and termination reactions, the criterion of a unified flammability exponent is extended to the current multi-component mixture system. This outcome yields useful insight into the fundamental processes of flammability limits, and scrutinizes the heat loss and chain termination effects of flammability limits. Results of this study provide guidance for hazard mitigation and fire suppression for the thermal runaway of lithium-ion batteries.
KW - Battery vent gas
KW - Flammability limits
KW - Inert gases
KW - Thermal runaway
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U2 - 10.1016/j.combustflame.2023.112631
DO - 10.1016/j.combustflame.2023.112631
M3 - Article
AN - SCOPUS:85147348575
SN - 0010-2180
VL - 249
JO - Combustion and Flame
JF - Combustion and Flame
M1 - 112631
ER -