The presented research project addresses the necessity to analyze and model the thermal behavior and thermal runaway (TR) of lithium-ion batteries, as well as to determine key parameters through appropriate measurement methods. In the future, retired traction batteries are intended for Second-Life applications, such as stationary energy storage. Effective Battery Thermal Management Systems (BTMS) are crucial for enhancing operational safety and reducing costs by preventing fault occurrences. In order to meet these requirements, characteristic aging effects must be considered for a State-Of-Health range well below 80%. In addition to measurement-based quantification, simulation techniques provide the opportunity to take into account changes in the thermal requirements of the BTMS due to ageing.

Comprehensive knowledge of the thermal stability and TR behavior of individual battery cells is vital for BTMS design. Key parameters include the temperature at the onset of exothermic decomposition, self-heating rate, maximum temperature, and heat release. Investigations of TR behavior in an Accelerating Rate Calorimeter (ARC) provide access to these data. Differential Scanning Calorimetry (DSC) yields reaction kinetics parameters (activation energy, frequency factor, reaction enthalpy) crucial for TR behavior modeling. Electrochemical impedance spectroscopy (EIS) characterizes battery cells non-destructively across various aging states, ideally offering insights into altered thermal behavior. Therefore, a combined process of established measurement methods and simulation models is being developed to describe the safety of aged lithium-ion cells and design propagation-inhibiting thermal management systems for second-life battery storage.