The analysis on the battery thermal management system with composite phase change materials coupled air cooling and fins

In this study, paraffin (PA) and expanded graphite (EG) were used to prepare composite phase change materials (CPCM). Through experimental study, the optimal axial thickness (45 mm) and radial thickness (8 mm) of CPCM have been found. Thus, based on the above results, a structure of BTMS using CMCP (PA/EG) coupled air cooling and fins (III-BTMS) was proposed to reduce the overall weight of the BTMS. It has been validated that the II-BTMS could meet the cooling performance requirements with 0 m/s air velocity in Li-ion battery at the 20 degrees C environmental temperature at 2C discharge rate. It means that in this condition, no extra energy is needed to cool the Li-ion battery of II-BTMS. The high discharge rate simulation shows that the cooling performance of III-BTMS is still better than the I-BTMS. In simulation results, it could be clearly observed that the fins could effectively decrease the flow dead zone in the III-BTMS model. Take Tesla automobile (model S) as an example, compared with using the I-BTMS, the b-type fin of III-BTMS module could at least reduce the weight of 45.84 kg in the study. The research results of III-BTMS are hoped to provide research ideas for the application of CPCM to EVs.

Automated summary

In this study, composite phase change materials (CPCM) were prepared using paraffin (PA) and expanded graphite (EG). The optimal thickness of CPCM was determined through experimental study. A new structure of BTMS was proposed to reduce overall weight, based on which the cooling performance requirements of Li-ion batteries were met without additional energy. Simulation results showed that the new structure had better cooling performance and decreased flow dead zone. The weight of the module was reduced using fins. The research results provide research ideas for the application of CPCM to electric vehicles.