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Here we report a method of simultaneously measuring internal short circuit (ISC) current, ISC resistance, and ISC temperature in large-format Li-ion cells to understand the behaviors of ISC-caused thermal runaway (TR). It is enabled by dividing electrodes and current collectors into a small segment and a large segment and triggering ISC in the small segment through slow nail penetration. ISC temperature and ISC current showed multiple peaks before TR, which was attributed to the change in ISC resistance as the nail went through different layers of cell components. TR occurred when the ISC resistance suddenly dropped by an order of magnitude. More interestingly, it was found that TR was confined to the small segment and did not propagate to the large segment. It was hypothesized that reduced heat transfer in the gap between the segments contributed to the confinement of TR. A comparison between a fully segmented cell and a cathode-segmented cell, with different effective thermal conductivity in the gap region, supported this hypothesis.
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This content will become publicly available on December 1, 2026
Suppressing internal short circuit caused thermal runaway of lithium-ion batteries through current modulation
We report a current modulation strategy that suppresses internal short circuit (ISC)-caused thermal runaway of Li-ion cells. The strategy works by guiding current flow outside a cell in the event of a serious ISC to reduce local internal heating. Using 4-Ah cells with NMC811 cathode and graphite anode, and a reliable ISC triggering and quantification method, we demonstrated that thermal runaway would start within a few seconds of Al-Anode ISC or Al-Cu ISC without current modulation. In comparison, thermal runaway was effectively suppressed with proper current modulation. Quantification through in situ diagnosis showed that current modulation reduced heat generation at the ISC location by an order of magnitude and reduced the maximum temperature dramatically. Further energy balance analysis and post-mortem analysis supported the hypothesis that the strategy of current modulation works by minimizing local heating and promoting uniform heating.
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- Award ID(s):
- 2240029
- PAR ID:
- 10660880
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Journal of Power Sources
- Volume:
- 660
- Issue:
- C
- ISSN:
- 0378-7753
- Page Range / eLocation ID:
- 238544
- Subject(s) / Keyword(s):
- internal short circuit, thermal runaway, lithium-ion batteries, current modulation
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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