Failure Analysis Methodology for Li-Ion Incidents

Abstract

The purpose of this article is to lay out a scientific methodology for investigating lithium ion (Li-ion) product failures. The discussion provides possible causes for an overheating Li-ion cell failure and covers processes involved in preventing Li-ion incidents. Performing a scientific root cause failure analysis involves systematically performing the failure analysis, which is explained in detail, to eliminate branches from the fault tree and arrive at the root cause of a given failure. Statistical analysis of Li-ion cells is provided, along with a recall determination of issues in Li-ion cells. The article also presents snapshots from actual Li-ion investigations selected from hundreds of investigations that have been performed by the authors at Exponent as far back as 1995.

Bridging the gap between academic and industry Li-ion battery research

“…However, these engineering and materials changes can generate new failure mechanisms, such as shorts through separators, deformed or torn current collectors, breached cell enclosures, and more. Thus, cell quality control and field failures are important challenges facing the Li-ion battery industry, and solving such problems involves understanding the complex interplay between chemical and mechanical properties of cell components ranging from the electrode level to the full cell level (Loud and Hu, 2007;Mikolajczak et al, 2012;Cai et al, 2020).…”