TENDENCY OF TEMPERATURE EVOLUTION AND DISTRIBUTION IN DEGRADED POUCH LI-ION BATTERIES: INSIGHTS FOR EARLY DETECTION USING INFRARED THERMOGRAPHY

초록

Lithium-ion batteries (LIBs) are among the most essential energy storage technologies and are extensively utilized in portable electronics, electric vehicles, and energy storage systems due to their high energy density and long lifespan. However, battery degradation poses significant safety risks. Compared to new batteries, degraded ones exhibit distinct characteristics, such as changes in temperature distribution and evolution, which can be measured and monitored using infrared (IR) thermography. This study investigates the evolution of temperature and its distribution on pouch Li-ion batteries' surface under high discharging current at various degradation periods. Three batteries were degraded by three simulation methods: Urban Dynamometer Driving Schedule (UDDS), Worldwide Harmonized Light Vehicles Test Procedure (WLTP), and Constant Current (CC). The findings indicate that as the battery's state of health (SoH) declines, both the average temperature and temperature variation increase. Additionally, the region with the highest temperature shifts from the positive electrode side to the center of the battery surface. These findings suggest the potential for early detection of degraded batteries through IR thermography technology during high current discharge.

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