Inclined U-shaped flat microheat pipe array configuration for cooling and heating lithium-ion battery modules in electric vehicles

Abstract The battery thermal management system (BTMS) is important to ensure the lithium-ion battery life, performance, and safety. A novel inclined U-shaped flat microheat pipe array (FMHPA) is used for BTMS to achieve high efficiency and space-saving in this study. The thermal control performance is experimentally studied and compared with the module without FMHPAs. Results show that the equivalent thermal conductivity of the inclined U-shaped FMHPA is approximately 4350 W m−1 K−1, and plays the role of core heat transfer element. The maximum temperature and temperature difference of the module with FMHPAs are reduced by 16% and 60%, respectively, compared with those of the module without FMHPAs; FMHPAs keep the module in a suitable temperature range for most of the time in the ambient temperature of 25 °C during the 1C charge–2C discharge cycle. Moreover, the temperature difference at cell and module level are maintained within 5 °C in ambient temperature of 25 °C and 40 °C. The heating rate of the module with FMHPAs reaches 0.61 °C/min under the temperature difference of less than 5 °C; variable power heating (from large to small) will increase the temperature rise rate of the battery by 0.19 °C/min.