A lumped model of venting during thermal runaway in a cylindrical Lithium Cobalt Oxide lithium-ion cell

• Published in: Journal of power sources Vol. 307; pp. 56 - 62
• Main Authors: Coman, Paul T., Rayman, Sean, White, Ralph E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-2016
• Subjects: 18650; Ejecta venting; Electrolyte venting; Isentropic flow equations; Thermal runaway; Ejecta venting; 18650; Isentropic flow equations; Thermal runaway; Electrolyte venting
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2015.12.088

This paper presents a mathematical model built for analyzing the intricate thermal behavior of a 18650 LCO (Lithium Cobalt Oxide) battery cell during thermal runaway when venting of the electrolyte and contents of the jelly roll (ejecta) is considered. The model consists of different ODEs (Ordinary Differential Equations) describing reaction rates and electrochemical reactions, as well as the isentropic flow equations for describing electrolyte venting. The results are validated against experimental findings from Golubkov et al. [1] [Andrey W. Golubkov, David Fuchs, Julian Wagner, Helmar Wiltsche, Christoph Stangl, Gisela Fauler, Gernot Voitice Alexander Thaler and Viktor Hacker, RSC Advances, 4:3633–3642, 2014] for two cases - with flow and without flow. The results show that if the isentropic flow equations are not included in the model, the thermal runaway is triggered prematurely at the point where venting should occur. This shows that the heat dissipation due to ejection of electrolyte and jelly roll contents has a significant contribution. When the flow equations are included, the model shows good agreement with the experiment and therefore proving the importance of including venting.
•A lumped model for analyzing thermal runaway during venting is presented.•The importance of including isentropic flow equations is investigated.•Using the flow equations provides a better understanding of thermal runaway.•The energy leaving the battery with the ejecta is quantified.•The model shows good agreement with experiments.