Mitigation of Failure Propagation in Multi-Cell Lithium Ion Batteries

Abstract

Lithium ion batteries are one of the main energy storage devices that have the potential to be fully integrated in electric grid applications and electric vehicles. Despite years of research in battery safety, there are still challenges associated with the complexity of system-level safety for large battery systems. There is a major gap of safety knowledge at the module or pack level on the effects on adjacent cells in a large-scale battery pack as one cell experiences failure. After the impacts and consequences are identified it is also important to determine mechanisms to mitigate the effects of a single cell failure to the entire pack. In this study, we analyze the failure behavior of small battery packs with 5 stacked pouch cells (LiCoO2 cathode, 3Ah) after thermal runaway is induced to a single cell with nail penetration as the failure initiation method. The first part of the study was to determine the SOC in which full propagation was identified. Different states of charge were tested, including 50%, 75%, 80% and 100% SOC. Complete propagation was observed for 80% and 100 % SOC as shown in Figure 1. The second part of the investigation focused on identifying passive thermal management approaches to mitigating failure propagation. Figure 2 presents the preliminary results using an aluminum heat sink, in which partial propagation was achieved. The results of this study could provide insightful information of the impacts of single battery failure in a pack and a base for future battery designs. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. Figure 1