Correlation Between Changes in Environmental Temperature and Performance of High-Discharge Lithium-Polymer Batteries

Electric vehicles (EVs) have been developed to solve environmental problems and the depletion of energy resources, and batteries have been used as their main energy source. The battery used in this study was a lithium polymer battery with the same chemical structure as lithium-ion. The use of a solid electrolyte has advantages, such as lack of leakage of electrolyte, high density per size, and convenient shape design. In this study, we analyzed the heat generation and performance characteristics of EV batteries through experiments on changes in environmental temperature. There is a difference in the heat generation depending on the discharge rate, and the performance characteristics of the battery improves as the environmental temperature rises. In the experiment, the battery discharge performance and heat generation were meaningful at 40 degrees C environmental temperature, the worst battery discharge performance and heat generation at -30 degrees C environmental temperature were 25.1 W (1 C), 81.0 W (2 C), and 151.5 W (3 C). In this study, the heat generation and performance characteristics of the battery were analyzed according to the change in the environmental temperature and discharge rate of the battery. We proposed a relationship between heat generation and environmental temperature in terms of discharge rate. The relationship is significant in designing thermal management system for battery powered devices.