Experimental study on a novel battery thermal management technology based on low density polyethylene-enhanced composite phase change materials coupled with low fins

Phase change materials (PCM) cooling has been considered as the most potential alternative to traditional battery thermal management (BTM) technology, but significant challenges remain: PCM leakage, poor mechanical properties and low surface heat transfer capability between PCM and the external environment. Here, we develop a BTM technology based on the ternary composite materials of expanded graphite (EG), paraffin (PA) and low-density polyethylene (LDPE) coupled with low fins. The as-doped LDPE framework can not only enhance the mechanical molding property but also prevent PA leakage to a great extent. Coupling with low fins endows the entire BTM system with high surface heat transfer capability. For instance, the as-prepared LDPE/EG/PA composite PCM shows much better mechanical properties and cooling effect in comparison to EG/PA composite and air cooling, respectively. After coupling with low fins, the as-constructed PCM-based battery module presents excellent heat dissipation performance, keeping the battery pack working under the safety temperature of 50 °C and temperature difference of 5 °C for lithium-ion power batteries, even at an extremely high discharge rate of 3.5 C.