Impact of system structure on the performance of a hybrid thermal management system for a Li-ion battery module

A hybrid thermal management system (TMS), which is the combination of an active TMS and a passive TMS, can maintain the battery temperature in an appropriate range while having a larger cooling capacity than a passive TMS and consuming less energy than an active TMS. In this paper, the role of the structure of a hybrid TMS that comprises an air cooling system (as an active TMS) and an embedded phase change material (as a passive TMS) is investigated for the first time. To this end, eighteen cases with different cell arrangement, module compactness, and phase change material (PCM) thickness are simulated and studied. The results show that only for case 1 (i.e., the case with the aligned arrangement of cells, maximum compactness, and least thickness of PCM layer), the rising of cells temperatures is unsafe. Besides, in all cases, the maximum temperature difference of the battery module does not exceed 1.5 °C, which demonstrates the excellent capability of the proposed hybrid TMS in creating uniform temperature distribution among the cells. The results demonstrate that by increasing the PCM layer thickness, the average temperature of the cells decreases, while the maximum temperature difference among the cells increases. [Display omitted] •A novel hybrid TMS comprising PCM around cells and air-cooling flow is proposed.•18 cases with different arrangement, compactness & PCM thickness are simulated.•Cell temperature rises safely and temperature difference never exceeds 1.5 °C.•Increasing of thickness lowers cell temperature & enlarges temperature difference.•Melting proceeds toward shells, but doesn't reach shells when PCM is 6 mm thick.