Citation

Gagnon L, Zeng D, Ditch B, Wang Y. Fire Safety J. 2023; 140: e103904.

Copyright

(Copyright © 2023, Elsevier Publishing)

DOI

10.1016/j.firesaf.2023.103904

PMID

unavailable

Abstract

Lithium-ion batteries are widely used in industry for their high energy density and long cycle life; however, they are sensitive to abuse, such as external heating. This study examines 63 Ah, NMC pouch cells at 100% state of charge being forced into thermal runaway (TR) through external side heating at rates ranging from 0.2 to 0.5 °C/s. The fastest heating rate was found to initiate TR earliest, but the peak surface temperatures achieved by all cells were found to be approximately equal. A delay between TR initiation on the heat-exposed surface of the cell and the opposite surface was observed as TR spread across the cell, with the duration found to increase with heating rate. A flaming condition occurred for all cells during TR. For the utilized range of heating rates studied, the radiant heat flux of the flame was found to be unaffected, and the peak chemical heat release rate showed no statistical trend due to the changes in cell heating. Cell mass loss throughout TR also appears to be independent of heating rate with more research required to further explore this parameter. This study provides an in-depth analysis of TR behavior in the context of single, large-format pouch cells, the results of which will be used to develop a future 1D model for cell-level TR that predicts TR propagation behavior in a module.

Language: en

Keywords

Cell-level thermal runaway; Hazard evaluation; Large-format pouch cells; Li-ion battery