The Current Interrupt Device (CID) in a cell is designed to electrically disconnect a cell if the internal pressure increases beyond a design point. If the gas pressure increases further the burst disc breaks and the gas is vented.
However, is the CID operation safe under High Voltages (HV)?
As the CID opens the circuit there is a possibility of creating an arc. The situation is very similar to the case of the arc generated when opening contactors under load.
Haß et al [1] have tested a number of cells in series in an overcharge test and at different system voltages. What they found was that in battery systems with a high system voltage of series-connected cylindrical cells, a voltage drop can occur at an open CID, which can lead to the formation of a critical arc. Consequently, the cell burns or can explode.
Considering the results of the first test series up to 120 V, it can be seen that the first critical cell behaviour occurs with NMC and NCA chemistries, while the LFP chemistry is safe in comparison and there are no ignitions or fires of hazard level 5 (EUCAR Hazard Levels) or higher.
Xu et al [3] found that the voltage required for an arc can be much lower, 19 V can initiate an arc when the CID disconnects, while 35 V is sufficient to sustain it.
This post has been built based on the support of and sponsorship from: Quarto Technical Services, Eatron Technologies and About:Energy
References
- Haß, J.; Schieber, C.; Meilinger, F.; Kotak, Y.; Sevinc, S.; Lang, P.; Schweiger, H.-G. Investigation of the Effects Caused by Current Interruption Devices of Lithium Cells at High Overvoltages. Appl. Sci. 2024
- Generic Safety, Handling and Qualification Guidelines for Lithium-Ion (Li-Ion) Batteries, NASA Aerospace Flight Battery Program
- Wenqiang Xu, Kai Zhou, Yalun Li, Bin Gao, Xiaogang Wu, Xinyu Rui, Yu Wu, Hewu Wang, Languang Lu, Minggao Ouyang, Study on the evolution laws and induced failure of series arcs in cylindrical lithium-ion batteries, Applied Energy, Volume 377, Part B, 2025
- A. Augeard, T. Singo, P. Desprez, F. Perisse, S. Menecier and M. Abbaoui, “Arc analysis to the CID of li-ion battery cells in high-current applications,” 2014 IEEE 60th Holm Conference on Electrical Contacts (Holm), New Orleans, LA, USA, 2014, pp. 1-7