Experimental investigation of the effect of charging and discharging on a battery module of cylindrical lithium-ion cells

The generation of heat in Li-ion batteries (LIBs) plays a crucial role in determining their performance, safety, and longevity, particularly when subjected to different charging and discharging rates. This study conducts an experimental analysis of heat production in cylindrical Li-ion cells at different C-rates: 0.5 C, 0.75 C, and 1 C, during both charging and discharging phases. Through experiments involving constant current (CC) – constant voltage charging and constant current discharging, the thermal and electrical properties of the cells are examined. The findings indicate that higher C-rates result in greater heat production, with charging producing more heat than discharging. At a 1 C rate, the temperature of the battery cell increases to about 45°C during charging and 35°C during discharging. It is also observed that the most heat is generated during the constant current charging process, while less heat is produced during constant voltage charging. These results highlight the importance of thermal management strategies, particularly at higher C-rates, to mitigate excessive temperature rises and enhance battery reliability. This study contributes to improving the design of battery thermal management systems, ensuring the safe and efficient operation of LIBs in electric vehicles.