Abstract
Battery performance and lifespan are greatly dependent on its temperature, and a good battery thermal system (BTMS) can make the battery work at its favorable temperature range, improve its electrical performance, and extend its lifespan. Due to the high heat conductivity and large surface area of flat heat pipe (FHP), the FHP-based BTMS can quickly remove the heat produced by the battery and improve the temperature homogeneity among cells in the pack. In this study, the FHP is applied to the BTMS, and the influence of its structure on the battery thermal dynamics is studied. Firstly, a coupled thermal model for the FHP-based BTMS is established and verified by the experiment. This model integrates the resistance-based thermal model of the battery and FHP model based on the thermal resistance network. Then, the effect of the structure parameters of FHP such as the thickness, porosity, and particle diameter of sintered wick on the thermal performance of the battery is investigated. According to the results, the temperature variation among battery cells rises significantly when the dimensionless thickness of the wick is greater than 0.7. Moreover, the change of the porosity and particle diameter of the wick results in a nonlinear development of the wick thermal resistance which finally changes the heat conductivity of the FHP and battery temperature. Finally, a neural network model (NNM) is used to establish the relationship between the FHP parameters and battery thermal performance for optimizing the BTMS structure. According to optimization result, the optimized FHP can keep the maximum battery temperature below 40°C at a discharge rate of 2C and reduce the temperature variation in the battery by 7.4%.
Highlights
Nowadays, electric vehicles have been developed rapidly due to energy conservation and emission reduction policies
The results show that flat heat pipe combined with air or liquid cooling shows great effect on battery thermal management
We first analyze the thermal performance of the battery-flat heat pipe (FHP) system at different discharge rates
Summary
Electric vehicles have been developed rapidly due to energy conservation and emission reduction policies. The maximum temperature difference in battery pack is decreased by 30% after the optimization on PCM thickness distribution These related studies have verified the feasibility of heat pipes in BTMS. Xu et al (2019) combined flat heat pipe with liquid cooling and simulated to analyze the enhanced heat conduction effect under different discharge rates. Considering the past studies, researchers have verified the effect of heat pipes applied to battery thermal management through simulation or experiments, and they have shown many good results These researches mainly focus on the configuration of the BTMS system and demonstrate the influence of operating conditions on battery thermal performance. The optimization of FHP structural parameters has not yet been considered in BTMS design to improve the temperature thermal performance of batteries. An optimization design method towards structural parameters of FHP is carried out in order to improve the battery thermal performance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
