Thermal Characterization of Lithium-Ion Batteries under Varying Operating Conditions

Despite the widespread adoption of lithium-ion batteries in various applications such as energy storage, concerns related to thermal management have been persisting, primarily due to the heat generated during their operation and the associated adverse effects on its efficiency, safety, and lifetime. Hence, the thermal characterization of lithium-ion batteries is essential for optimizing the layout of the battery cells for a pack design and the corresponding thermal management system. This study focuses on an experimental investigation of heat generation of Li-ion batteries under different operating conditions, including charge-discharge rates, ambient temperatures, states of charge, and compressive pressure. The experiments were conducted using a custom-designed multifunctional calorimeter, enabling precise measurement of the heat generation rate of the battery and the entropy coefficient. The measured results have shown a good match with the calculated heat generation rate. Additionally, heat maps that show the influence of the operating conditions on the cell’s thermal performance are proposed. By offering a detailed and intuitive visualization of how different parameters impact heat generation and dissipation, these maps serve as a vital tool for battery pack engineers to optimize the design of thermal management systems.