Research on Thermal Dissipation Characteristics of Power Lithium-Ion Battery Module with Phase Change Cooling

Abstract

As an important part of battery electric vehicles, lithium-ion batteries will generate much heat in the working process. If heat dissipation measures are not taken in time, the accumulated heat will have a great impact on the battery temperature rise, seriously causing some battery safety incidents. To solve the cooling problem of lithium-ion batteries during charging and discharging cycle, in this paper, a square cooling module of lithium-ion power battery with phase change material (PCM) was designed, whose heat production and heat dissipation were established, which were coupled with the air-cooling heat dissipation model. Finally, a two-dimensional active and passive heat dissipation model of lithium battery module was formed, based on the thermal model, the simulation module in ANSYS Fluent was made use of simulating the thermal dissipation characteristics. The simulation results show that when the coefficient of convective heat transfer is 12, 60, 120W/(m2·K), the highest temperature of the battery module is 142.8℃, 74.6℃, 41.9℃, respectively, which indicates that the coefficient has an important influence on its maximum temperature. Secondly, during the whole charging-discharging cycle, its maximum temperature is 82.2℃, 79.1℃, 77.7℃and 75.1℃, respectively, when the standing time is 0, 5, 10 and 20min. Obviously, increasing the standing time can reduce its maximum temperature. In addition, the continuous heat accumulation will lead to the failure of PCM, at this time, the PCM needs to be coupled with other cooling technologies such as forced air cooling.