Experiment and simulation of thermal management for a tube-shell Li-ion battery pack with composite phase change material

A novel tube-shell Li-ion battery pack with a passive thermal management system (TMS) using composite phase change material (PCM) was designed to control cells temperature rising and improve battery module heat transfer. The battery pack consisted of expanded graphite (EG)/paraffin composite, aluminum tubes, baffles and a shell. EG/paraffin was applied to control cells temperature rising and create a thermal balance from one cell to another. The TMS was coupled with a forced air cooling to initialize PCM temperature (PCM solidification). In order to evaluate the effect of the baffles on improving air fluid heat transfer, a three dimensional numerical model of the tube-shell battery module with forced air cooling was performed using ANYSYS FLUENT. The thermal characteristics of the tube-shell battery pack were investigated both experimentally and numerically. The results show that: (1) EG/paraffin composite significantly reduces cells temperature rising and keeps the maximum temperature difference across the battery module within a low value of 1-2 °C. The tube-shell battery module with EG/PCM exhibits high heat dissipation efficiency. (2) The baffles change the air fluid flow direction, improving the interaction of fluid and its heat transfer efficiency.