Experimental investigation on thermal management of cylindrical Li-ion battery pack based on vapor chamber combined with fin structure

In electric vehicles, the performance of the power battery is closely related to its operating temperature, which makes it necessary to develop an effective and compact thermal management system. In this paper, a novel battery thermal management system for cylindrical Li-ion battery pack based on vapor chamber combined with fin structure is developed. A set of experiments concerning temperature control performance of the system under different discharge rates (2C, 3C, 5C) at ambient temperature of 25 degrees C is conducted. Subsequently, the effects of heat dissipation area, flow rate and way of condensation (air-forced cooling and water cooling) on cooling performance of the system are investigated and analyzed. The results show that the vapor chamber can notably alleviate the average temperature rise and improve the uniformity of temperature distribution within the battery pack. Furthermore, with the rising of dissipation area, the temperature control effect of the system becomes more effective. In addition, comparing to air-forced cooling, the system hybridized with water cooling exhibits lower maximum temperature and more uniform temperature distribution. However, flow rate has little effect on cooling performance. The above results indicate that applying vapor chamber combined with fin structure is a viable solution to thermal management of Li-ion battery pack.