Thermal Management Challenges in Lithium-Ion Batteries: Understanding Heat Generation Mechanisms

This paper investigates heat generation in commercial 18650 lithium-ion battery cells and the thermal management challenges stemming from their high energy density and electrochemical processes. Thermal effects can degrade performance, accelerate aging, and increase thermal runaway risk. Using isothermal calorimetry and electrochemical impedance spectroscopy (EIS), the study emphasizes optimizing thermal behavior to improve battery efficiency, safety, and durability. As the demand for high-performance lithium-ion batteries (LIBs) continues to rise, particularly in electric vehicles (EVs), electric vertical takeoff and landing (EVTOL) vehicles, and large-scale energy storage systems, managing thermal behavior has become a critical challenge. LIBs are valued for their high energy density, long lifespan, and efficiency, making them the dominant energy storage technology in modern applications. However, their performance, safety, and longevity are directly influenced by their ability to handle the heat generated during the charge-discharge process and rest cycles. Improper thermal management can lead to capacity degradation, reduced efficiency, accelerated aging, and, in extreme cases, catastrophic safety hazards such as thermal runaway. Addressing these thermal challenges is essential to ensure the safe and reliable operation of LIBs across a wide range of demanding applications.