Flexible Composite Phase-Change Material with Shape Recovery and Antileakage Properties for Battery Thermal Management

Considering the assembly and application in electric vehicles, battery thermal management systems (BTMSs) with phase-change materials (PCMs) are restricted by fluid leakage, high rigidity, and low thermal conductivity. Herein, a flexible composite phase-change material (CPCM) with high thermal conductivity and low leakage has been prepared and utilized in the battery module. Poly(ethylene glycol) (PEG) as a phase-change component, styrene–butadiene–styrene (SBS) as a support material, and ethylene–propylene–diene monomer (EPDM) as a synergistic support material could significantly improve the flexibility of CPCM. Moreover, aluminum nitride (AlN) was selected to improve the heat-transfer performance as well as to reduce temperature difference in the battery module. In this regard, flexible CPCM assembled in the battery module exhibited advantages of a compact structure and high efficiency, which were compared with various thermal management approaches and analyzed at different discharge rates. The results indicated that the flexible CPCM exhibited excellent temperature controlling capacity, especially at 3C discharge rate, the maximum temperature could be effectively sustained below 45.3 °C, and the temperature differences were maintained within 5.3 °C. Even under the test situation of 10 charge/discharge cycles, it still displayed a stable temperature control performance. These outstanding shape recovery and antileakage performances of the AlN-based flexible CPCM provide superior cooling efficiency and stability to the corresponding battery modules, which would provide insights into battery thermal management having the desirable assembly method and process flexibility.