Thermal management system for power batteries based on flat heat pipes

For the situation where the battery pack composed of lithium-ion batteries operates under conditions with significant heat generation, a thermal management system for a power battery flat heat pipe (FHP) suitable for low temperatures (10 °C) and high-rate discharge (2C) has been designed. A co-simulation platform combining an electrochemical-thermal coupled battery model and a multi-heat-source thermal resistance network model for the FHP was established and experimentally validated. The results show that the system reduces the battery pack's maximum temperature by 8.63 K and the temperature difference by 10.67 K, at 10 °C and 2C discharge, compared to the condition of pure air cooling. Increasing FHP total thickness from 3 mm to 7 mm lowers the maximum temperature by 8.43 K and the average temperature difference by 4.82 K. Higher external airflow enhances condenser heat dissipation, reducing maximum temperature but increasing the average temperature difference. Conversely, increasing the FHP total thickness or decreasing the dimension-one wick thickness, τ_w, improves the FHP thermal conductivity, with reducing both maximum temperature and average temperature difference, where, τ_w = t_w / (t_w + t_v), t_w is the wick thickness, t_v is the vapor chamber thickness. Experiments confirm accuracy of the model.