Abstract
High voltage and energy density have increased the use of lithium-ion batteries (LiBs) in many applications, including consumer electronics, electric vehicles, and grid-tied energy storage systems (ESS). However, with increasing energy density and installation size come heightened concerns about safety, including the risk of thermal runaway and serious fires. To understand the risks and outcomes of LiB failure, numerous studies have examined the response of fresh cells to mechanical, electrical, and thermal abuse. However, given the expected lifetime of LiBs, it is critical to consider the abuse response of aged cells. In this presentation, we review previous results on the abuse of aged cells to facilitate understanding of how aging conditions (such as temperature and cycle rate) and abuse methodology (including calorimetry, short circuit, and overcharge) impact key metrics of safety relative to fresh cells. In general, the conditions used to produce aged cells in these studies have involved extreme temperatures. Thus, we also share more recent calorimetry of cells aged to 80% capacity by relatively mild protocols to understand the abuse response of cells from more typical device operating conditions. These results facilitate a more data-informed risk assessment of aged energy storage systems and the development and adoption of appropriate failure mitigation strategies.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & 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.