Low-order modeling of Lithium Cobalt Oxide Lithium ion battery arrays with various states of charge

Abstract

Over the past two decades, Lithium-ion (Li-ion) batteries have become ubiquitous in society. Li-ion energy storage systems (ESS) are generally safe, but can fail under abnormal conditions potentially resulting in a catastrophic event known as thermal runaway (TR). During TR, internal cell exothermic reactions can result in high temperatures (∼ 800–1000 °C) and produce flammable, toxic gas. Abuse testing experiments were conducted with arrays of lithium-cobalt-oxide (LCO) Li-ion, pouch-format cells at three different states of charge (SOC). These experimental data were then used to create a low-order computational model and calibration methodology for predicting TR propagation in cell arrays. This work provides an alternative to more complex and expensive multi-reaction kinetic models shown in the literature. This model also includes an implementation for modeling different SOCs which has been underrepresented in the literature. The effect of SOC is discussed from experimental and computational results, along with comparison to the theory presented in the literature. The experimental data, computational model, and calibration methodology can be used for making decisions regarding TR prevention, detection, and mitigation strategies for large Li-ion ESS.