(Best Presentation Award - 3rd Place) Evaluating the Safety Limits of Soft Shorting in Li-Ion Batteries

Abstract

This study aims to redefine the safety limitations of lithium dendrite soft shorting in lithium-ion batteries using isothermal microcalorimetry and thermal reduction tests. Lithium dendrites are generally assumed to pose a safety risk by causing fatal short circuits, which can lead to thermal runaway and catastrophic battery failure. This assumption has led to massive amounts of time and capital on dendrite suppression and elimination research.Thermal reduction tests on delithiated lithium cobalt oxide were conducted to determine the absolute temperature at which thermal runaway occurs in one of the most volatile conventional systems. Isothermal microcalorimetry was conducted on the same system to measure the heat generated by the soft short circuit. Our results showed that the absolute temperature generated by the lithium dendrite soft short circuit was significantly less than the onset of thermal runaway via a thermal reduction route. These findings challenge the general assumption that lithium dendrites will directly lead to thermal runaway events in lithium-ion batteries.Our study suggests that while lithium dendritic shorting may pose a safety risk in lithium-ion batteries, it will not directly lead to a catastrophic thermal event. Further research is needed to explore the potential implications of deactivating the metallic lithium in the system via this soft shorting pathway.