Citation

Finegan DP, Darcy E, Keyser M, Tjaden B, Heenan TMM, Jervis R, Bailey JJ, Vo NT, Magdysyuk OV, Drakopoulos M, Michiel MD, Rack A, Hinds G, Brett DJL, Shearing PR. Adv. Sci. (Weinh.) 2018; 5(1): e1700369.

Affiliation

Electrochemical Innovation LabDepartment of Chemical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK.

Copyright

(Copyright © 2018, John Wiley and Sons)

DOI

10.1002/advs.201700369

PMID

29375967

PMCID

PMC5770664

Abstract

As the energy density of lithium-ion cells and batteries increases, controlling the outcomes of thermal runaway becomes more challenging. If the high rate of gas generation during thermal runaway is not adequately vented, commercial cell designs can rupture and explode, presenting serious safety concerns. Here, ultra-high-speed synchrotron X-ray imaging is used at >20 000 frames per second to characterize the venting processes of six different 18650 cell designs undergoing thermal runaway. For the first time, the mechanisms that lead to the most catastrophic type of cell failure, rupture, and explosion are identified and elucidated in detail. The practical application of the technique is highlighted by evaluating a novel 18650 cell design with a second vent at the base, which is shown to avoid the critical stages that lead to rupture. The insights yielded in this study shed new light on battery failure and are expected to guide the development of safer commercial cell designs.

Language: en

Keywords

Li‐ion batteries; X‐ray CT; high‐speed imaging; thermal runaway; venting