Modeling cell venting and gas-phase reactions in 18650 lithium ion batteries during thermal runaway

JOURNAL OF POWER SOURCES

卷:489

Article

Kim, Jinyong¹  Mallarapu, Anudeep¹  Finegan, Donal P.¹  Santhanagopalan, Shriram¹ 

[1] Natl Renewable Energy Lab, Ctr Energy Convers & Storage Syst, Golden, CO 80401 USA

关键词: Cell venting;    Thermal runaway propagation;    Computational fluid dynamics simulations;    Turbulent flow battery models;    Battery safety;    Battery modeling and simulations;   

DOI  :  10.1016/j.jpowsour.2021.229496

来源: Elsevier

【 摘 要 】

A numerical model is developed to study cell venting, internal pressure, and gas-phase dynamics behavior of 18650 Li-ion cells undergoing thermal runaway. A k-epsilon Reynolds-Averaged Navier-Stokes (RANS) model is adopted to describe the turbulent flow out of the cells, while the fluid dynamics inside the cells is described by Darcy-Forchheimer's equation. Thermal abuse reactions and gas generation kinetics are described by a single-step lumped reaction model. Then, a series of computational fluid dynamics (CFD) simulations are conducted on a single 18650 cell at various states-of-charge (100%, 50%, 25%) to study detailed flow and thermal behavior as a function of quantity of gas generated during cell venting. Venting events are categorized into two stages: i) breaching of the cell container and ii) thermal runaway reactions. It is found that the cell response is dominated by the second stage since most of the gases are generated during thermal runaway. Also, the propensity for propagation is highly affected by state-of-charge (SOC). Cells at higher SOCs produce more heat and gas during the venting event, owing to higher mass and concentrations of reacting gases, and consequently reach higher internal cell pressures which increase the risk of side-wall breaching.

【 授权许可】

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