IZM

Lithium-ion cell thermal runaway ejecta behavior is highly complex due to the rapid and violent release of solids, liquids, and gases, each exhibiting unique thermal and chemical dynamics. When a cell undergoes thermal runaway, internal temperatures can exceed 1000 °C, causing electrode materials, separators, and electrolyte components to degrade and expel high-temperature particulates, molten metals, and vaporized electrolyte. The gaseous ejecta, consisting of flammable hydrocarbons, carbon dioxide, hydrogen, and more, can ignite upon exposure to oxygen, generating intense jet flames and secondary fire hazards. Liquid ejecta, including decomposed electrolyte and melted separator materials, can form highly conductive residues, increasing the risk of electrical shorts. Solid ejecta, such as fragmented casing or electrode debris, can be ejected with high velocity, posing mechanical hazards and contributing to thermal propagation in battery packs. 

The interaction between these ejecta phases results in difficult to characterize heat transfer dynamics, further complicating containment and mitigation strategies. Understanding the behavior of ejecta is critical for designing safer battery enclosures, venting mechanisms, and thermal barriers in applications where battery safety is critical. KULR has developed a technique referred to as impingement zone mapping (IZM) to help provide data necessary for understanding ejecta behavior as a function of cell type and trigger method. Thermal data, IR videography, and 360 view high speed videography are collected in parallel for each experiment.