Forensic Analysis of Lithium-Ion Cells Involved in Fires 14-13-03-0023

The emerging use of rechargeable batteries in electric and hybrid electric vehicles and distributed energy systems, and accidental fires involving batteries, has heightened the need for a methodology to determine the root cause of the fire. When a fire involving batteries takes place, investigators and engineers need to ascertain the role of batteries in that fire. Just as with fire in general, investigators need a framework for determining the role that is systematic, reliant on collection and careful analysis of forensic evidence, and based on the scientific method of inquiry. This article presents a systematic scientific process to analyze batteries that have been involved in a fire. It involves examining Li-ion cells of varying construction, using a systematic process that includes visual inspection, x-ray, CT scan, and possibly elemental analysis and testing of exemplars. For the purposes of this article, we are mainly concentrating on the most common designs of consumer lithium-ion batteries, cylindrical and pouch. The methodology applies both scientific literature and observations gathered while investigating over a thousand incidents.