Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MM: Fachverband Metall- und Materialphysik

MM 40: Focus Session: Battery Materials – Experimental Characterisation and Safety Testing (joint session KFM/MM)

MM 40.3: Vortrag

Mittwoch, 20. März 2024, 15:50–16:10, EMH 225

Thermal Runaway analysis of lithium-ion batteries with different electrolyte compositions — •Karsten Geuder, Hans Jürgen Seifert, and Carlos Ziebert — Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany

Investigation of the safety of lithium-ion batteries, particularly with respect to thermal runaway, is critical because of the wide application of these batteries. This study specifically examines the influence of electrolyte and additives on battery safety and aims to improve our understanding of thermal runaway in full cells through comparative analysis.

Unlike commercial lithium-ion batteries, the electrolyte composition is well known. The control electrolyte of the 1Ah pouch cells is a 3:7 mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC). In addition, we used the control electrolyte with either 5% vinylene carbonate (VC) or 5% fluoroethylene carbonate (FEC). To assign the different thermal processes and reactions in the full cells, the dry cells were disassembled and the components were analyzed by differential scanning calorimetry. The full cells were characterized for their thermal runaway behavior using both Heat-Wait-Seek and overcharge tests in accelerating rate calorimeters. We were able to correlate the endothermic behavior of the full cell at about 115 °C with the onset of separator melting. A comprehensive understanding of thermal runaway is critical to ensuring the safety of lithium-ion batteries. An accurate understanding of the electrolyte composition provides deeper insight into its safety implications.

Keywords: lithium-ion battery; electrolyte; safety