Battery thermal management based on multiscale encapsulated inorganic phase change material of high stability

This paper proposes a battery thermal management system with an inorganic phase change material(PCM). A multiscale encapsulation method is presented to solve the inherent problems of the inorganic PCM-sodium acetate trihydrate (SAT)-Urea. This method adopts microscale encapsulation with expanded graphite (EG) to enhances the thermal conductivity of the PCM to 4.96 W/m.K and eliminates the liquid leakage. Further macroscale encapsulation with the organosilicon sealant significantly improves the long-term stability of the salt hydrate, because it completely cuts off the dehydration channel of the salt hydrate, maintaining a stable composition in the PCM. This effective multiscale encapsulation paves the way of applications of the inorganic PCMs in Li-ion battery thermal management. This inorganic PCM is compared with an organic PCM in the fire resistivity and cooling performance for a 20-cell battery pack. The results confirm that the inorganic PCM is safer because it is not flammable and offers a cooler but a more uniform thermal environment for the battery. The competitive inorganic PCM owns advantages in price, safety and cooling performance, showing great prospects in commercial battery thermal management systems.

Automated summary

This paper presents a battery thermal management system using an inorganic phase change material (PCM) with a multiscale encapsulation method. The use of expanded graphite at microscale and organosilicon sealant at macroscale enhances the thermal conductivity and stability of the PCM, paving the way for applications in Li-ion battery thermal management. The inorganic PCM demonstrates superior fire resistivity and cooling performance compared to organic PCM, making it a safer and more effective option for commercial battery thermal management systems.