Characterizing thermal distribution of electric heating plates for power battery

Abstract

Electric preheating of power batteries within specific temperature ranges is recognized as a promising technology for enabling fast charging and discharging. Among various methods, electric heating plate (EHP) has gained widespread attention. Nevertheless, its performance remains insufficiently understood. In this study, the EHP is comprehensively characterized through the construction of a realistic three-dimensional transient model, which is experimentally validated. Detailed analysis is conducted on the influence of resistance wire (RW) width and thermal power, with a particular focus on temperature profiles and uniformity. The results show that a circular fillet structure is recommended to ensure uniform current distribution in RW instead of the traditional right-angle fillet structure. The temperature of the EHP gradually decreases from its center to the outwards, forming an O-shape distribution of isotherm. The temperature uniformity and maximum temperature difference are primarily determined by the width and spacing of RW, demonstrating a positive correlation. Our finding also reveals that an EHP with a RW width of 1 mm displays a maximum temperature difference within ±0.5 K, meeting the requirements imposed by major industrial power battery producers. These results not only provide guidance for optimizing EHP architecture but also support enhanced performance in the fast charging and discharging of power batteries.