Adiabatic calorimetry test of the reaction kinetics and self-heating model for 18650 Li-ion cells in various states of charge

• Published in: Journal of power sources Vol. 318; pp. 200 - 209
• Main Authors: Chen, Wei-Chun, Wang, Yih-Wen, Shu, Chi-Min
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.06.2016
• Subjects: Adiabatic calorimetry; Adiabatic flow; Calorimetry; Chemical kinetics; Electric cells; Electric charge; Explosions; Lithium batteries; Mathematical models; Pseudo-zero-order reaction; States of charge; Thermal explosion energy; Thermal runaway; Pseudo-zero-order reaction; States of charge; Thermal explosion energy; Chemical kinetics; Adiabatic calorimetry
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2016.04.001

Use of adiabatic calorimetry to characterise thermal runaway of Li-ion cells is a crucial technique in battery safety testing. Various states of charge (SoC) of Li-ion cells were investigated to ascertain their thermal runaway features using a Vent Sizing Package 2 (VSP2) adiabatic calorimeter. To evaluate the thermal runaway characteristics, the temperature-pressure-time trajectories of commercial cylindrical cells were tested, and it was found that cells at a SoC of greater than 50% were subject to thermal explosion at elevated temperatures. Calorimetry data from various 18650 Li-ion cells with different SoC were used to calculate the thermal explosion energies and chemical kinetics; furthermore, a novel self-heating model based on a pseudo-zero-order reaction that follows the Arrhenius equation was found to be applicable for studying the exothermic reaction of a charged cell. •Adiabatic calorimetry is applied to the study of thermal runaway in Li-ion cells.•A self-heating model was developed based on pseudo-zero-order Arrhenius kinetics.•Thermal explosion energy increases exponentially with SoC.