Role of heat-pipe thermal spreader on the thermal management of light-weight battery module and suppression of thermal runaway

<p>A novel air-cooling battery thermal management system integrated with L-shaped heat-pipes and thermal spreader is proposed for both ultra-high C-rate and thermal runaway suppression applications. Cylindrical batteries in 5×4 array are connected structurally with a thermal spreader embedded with finned L-shaped heat-pipes aligned to the air flow direction. The heat-pipes, which enable rapid temperature equalization of the upstream and downstream batteries, are characterized by the specially developed test jig. Both numerical simulation and experimental test are conducted to examine the thermal performances of battery module under varying discharge rates from 1C to 5C and air velocities from 1m/s to 5m/s. An experimental test for the battery module incorporating L-shaped heat-pipes was also conducted to verify the numerical simulation, with excellent agreement achieved. Under ultra-high discharge rates of 5C, the maximum temperature and the maximum temperature difference of the battery module at 5m/s vs 2m/s decrease by 15.92% and 28.79%, respectively, meeting the thermal requirements. Increasing the number of fins can further improve the thermal performance of the battery module. Besides, the battery module also demonstrates effective suppression of thermal runaway propagation. In the event of thermal runaway occurring in a single battery, the surrounding batteries reach 78.69°C maximum, well below the thermal runaway temperature, and thus successfully suppress the thermal propagation. Clearly the present study presents new ways to push the air-cooling limit for high performance light-weight battery packs.</p>