Contribution to the Study of Electric Arcs in Lithium-Ion Batteries

This paper deals with the safety devices incorporated in the most commercial 18650 lithium-ion (Li-ion) cells. The systems have been effective at cell level, but with the development of Li-ion cells in module or battery pack configurations, safety device breakdown occurs during battery operation. The 18650 cells include a current interrupt device (CID), which manages cell overcharge by opening the circuitry when an overpressure event occurs. But CID opening under high voltage can undergo electric arcs and it can lead to a thermal runaway in the most extreme cases. First, in this paper, the general risks that exist in batteries and the related protection technologies are reviewed. This review is completed by arcing tests by contact opening and an arc behavior analysis. This paper also analyzes the direct current electric arc risks and damages that can occur to the mechanical safety vent pressure of the cylindrical 18650 Li-ion batteries during CID opening. In addition, an assessment of the electric arc risks related to the battery system and at CID level is performed. This paper will shed light to the electric arc phenomena and reduce the arcing risk in Li-ion batteries. The proposed solutions are a step toward the arc risk mitigation.