In this work, commercial 18650 lithium-ion cells with LiMn2O4, LiFePO4, and Li(Ni0.33Mn0.33Co0.33)O2 cathodes were exposed to external heating in an accelerating rate calorimeter (es-ARC, Thermal Hazard Technology (THT), Bletchley, UK), to investigate the thermal behavior under abuse conditions. New procedures for measuring the external and internal pressure change of cells were developed. The external pressure was measured utilizing a gas-tight cylinder inside the calorimeter chamber, in order to detect the venting of the cells. For internal pressure measurements, a pressure line connected to a pressure transducer was directly inserted into the cell. During the thermal runaway experiments, three stages (low rate, medium rate, and high rate reactions) were observed. Both the pressure and temperature change indicated different stages of exothermic reactions, which produced gases or/and heat. The onset temperature of the thermal runaway was estimated according to the temperature and pressure changes. Moreover, the different activation energies for the exothermic reactions could be derived from Arrhenius plots.

Experimental Analysis of Thermal Runaway in 18650 Cylindrical Li-Ion Cells Using an Accelerating Rate Calorimeter

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

http://wrap.warwick.ac.uk/161908/1/WRAP-coupled-conjugate-heat-transfer-CFD-thermal-runaway-jet-fire-18650-lithium-ion-thermal-abuse-2022.pdf

A coupled conjugate heat transfer and CFD model for the thermal runaway evolution and jet fire of 18650 lithium-ion battery under thermal abuse

Lithium-ion (Li-ion) batteries have been utilized increasingly in recent years in various applications, such as electric vehicles (EVs), electronics, and large energy storage systems due to their long lifespan, high energy density, and high-power density, among other qualities. However, there can be faults that occur internally or externally that affect battery performance which can potentially lead to serious safety concerns, such as thermal runaway. Thermal runaway is a major challenge in the Li-ion battery field due to its uncontrollable and irreversible nature, which can lead to fires and explosions, threatening the safety of the public. Therefore, thermal runaway prognosis and diagnosis are significant topics of research. To efficiently study and develop thermal runaway prognosis and diagnosis algorithms, thermal runaway modeling is also important. Li-ion battery thermal runaway modeling, prediction, and detection can help in the development of prevention and mitigation approaches to ensure the safety of the battery system. This paper provides a comprehensive review of Li-ion battery thermal runaway modeling. Various prognostic and diagnostic approaches for thermal runaway are also discussed.

/pdf/a-review-of-lithium-ion-battery-thermal-runaway-modeling-and-183tyxkk.pdf

A Review of Lithium-Ion Battery Thermal Runaway Modeling and Diagnosis Approaches

Experimental study on thermal runaway and fire behaviors of large format lithium iron phosphate battery

Simulating onset and evolution of thermal runaway in Li-ion cells using a coupled thermal and venting model

The current interrupt device (CID) and vent mechanism in the cap of 18650 lithium-ion cells decrease thermal runaway risks by electrically isolating the cell upon internal pressure increase and relieving internal pressure before case rupture, respectively. Geometry analysis, CID- and vent-activation pressure measurement, and finite element analysis mechanical simulation of the vent mechanism were performed for MTI and LG MJ1 18650 caps. The MTI cap used a spot-weld and the LG MJ1 cap used a notch-groove connection for the CID. The vent-activation mechanism was a notch-grooved disk for both caps. The CID-activation pressures were 1.058 ± 0.053 and 1.293 ± 0.119 MPa at ambient temperature and 0.920 ± 0.076 and 1.066 ± 0.068 MPa at 100°C for the MTI and LG MJ1 caps, respectively. The vent-activation pressures were 2.308 ± 0.196 and 2.202 ± 0.083 MPa at ambient temperature and 1.919 ± 0.132 and 1.866 ± 0.084 MPa at 100°C for the MTI and LG MJ1 caps, respectively. Mechanical simulations predicted vent-activation pressures in agreement with experiments and showed decrease maximum stress sensitivity to applied pressure near the vent-activation pressure, consistent with observed sample-to-sample vent-activation pressure variation. Mechanical simulation also predicted vent-activation pressures of 0.448 and 0.400 MPa for the MTI and LG MJ1 caps, respectively, at 300°C.

Weisi Li

Papers

Simulating onset and evolution of thermal runaway in Li-ion cells using a coupled thermal and venting model

Comparison of Current Interrupt Device and Vent Design for 18650 Format Lithium-ion Battery Caps

Simplified Pouch Cell Method for 3-Electrode Re-Testing of Harvested Double-Sided Electrodes From Commercial Lithium-Ion Batteries

LG MJ1 Vent Cap CT Scans

MTI 18650 Vent Cap CT Scans