Energy Release Quantifications for Li-ion Battery Failures

Lithium-ion batteries have become the energy storage technology of choice, spanning applications in transportation, utilities, consumer electronics, aerospace, and medical devices. As Li-ion battery chemistries have improved, battery energy and power densities have increased, raising the risk of potential battery failures, including thermal runaway.

Featured on the cover of the November 2022 issue of "In Compliance" magazine, "Energy Release Quantification For Li-Ion Battery Failures" written by Exponent battery experts Francesco Colella, Sergio Mendoza, Tim Myers, Ryan Spray, Artyom Kossolapov, and Michael Barry proposes evaluation and testing strategies to help reduce the risk of catastrophic failure, which can also help support the design of safer products.

"The heat generated by one failed cell in a large multi-cell pack, such as those commonly used in electric vehicles or stationary energy storage systems, can heat up neighboring cells which may lead to a thermal cascade through the battery pack, presenting an increased risk to property and safety," the authors write.

From the publication: "One reason for the concern over the propagation of failures is that thermal runaway events can result in the venting of flammable gases, and these gases can generate a fire or an overpressure event if ignited in a confined area."  

The output of the article is a framework that relies on four experimental methodologies that include sealed vessel testing, oxygen consumption calorimetry testing, accelerating rate calorimetry, and fractional thermal runaway calorimeter.

"Combined, these techniques offer quite a complete picture of the energy and materials released during the thermal runaway of a lithium-ion battery," the authors write.