Flame-retardant phase-change aerogel: Experimental characterization and battery thermal management simulation

As the primary energy source for electric vehicles, maintaining an appropriate working temperature is essential for improving the lifespan of electric vehicle batteries. In addition, it is critical to prevent the damage and loss associated with thermal runaway, which can lead to fire and explosion. To address the need, a phase-change material aerogel is introduced that is created by embedding microencapsulated phase-change materials (MEPCMs) into silica aerogel. MEPCMs utilize n-octadecane as a phase-change material, which exhibits a phase-change enthalpy of 180 J/g and an encapsulation efficiency of 77 %, while also demonstrating stability in retaining their fundamental properties after 200 cycles. In addition, the method of physically blending and employing van der Waals forces to bond MEPCMs with the aerogel effectively avoids the cumbersome procedures and leakage problems caused by pouring molten phase-change materials into aerogels, as seen in previous studies. The approximate phase transition temperature and high enthalpy ensure that the composite can absorb excess heat. Moreover, the composite aerogel maintains a lightweight density of 0.2 g/cm³ and LOI of around 25 %. Additionally, the data measured during the experimental characterization were used to study the thermal management performance of phase-change aerogels through Computational Fluid Dynamics analysis. The results indicate that the temperature of lithium-ion batteries can be controlled within a reasonable range during operation at different discharge rates. The research has the potential to inspire innovative material designs for enhancing battery thermal management.