The propagation of a local thermal runaway event to adjacent cells will determine the severity of potential local thermal abuse events in large battery packs relevant to transportation or grid-scale storage. Propagation can occur or heat can be dissipated depending on the ratio of the thermochemical reaction rates to the heat transfer rates. Also of importance is the thermal capacity of a system relative to the thermal energy released. We demonstrate these phenomena with recently developed thermochemical models for thermal abuse scenarios. These models have been developed with greater fidelity for high temperature heat release rates that we will show are important. Predictions are compared with recent experiments where thermal runaway was initiated through thermal abuse of one cell and subsequent cascading propagation, or failure to propagate, through the remaining cells in a pack, depending on the energy stored and the thermal characteristics of the battery pack. Implications for cascading failure in larger systems are discussed.

^{Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.}

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