Preparation and Application of Aluminum-Phenylphosphinate-Encapsulated Phase Change Materials for Thermal Management of Lithium-Ion Batteries

With the wide application of lithium-ion batteries, the thermal management of lithium-ion batteries had become increasingly important as a result of reducing the incidence of thermal runaway (TR) accidents of lithium-ion batteries. In this article, a new type of microcapsule composite phase change material (CPCM) was prepared by the in situ polymerization method and applied to the thermal management of lithium-ion batteries. High latent heat paraffin (PA) was used as the phase change material (PCM); expanded graphite (EG) was used as the thermally conductive enhancement material; and flame-retardant additive aluminum phenylphosphinate (PADP) was used as the encapsulation material. Chemical and microstructure analysis of the material was analyzed using scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Thermal stability of the material was tested using differential scanning calorimetry and thermogravimetry. Thermal conductivity and fire resistance were further analyzed. Experimental results revealed that CPCM with a nuclear/matrix material ratio of 3:1 had the best thermal storage properties and flame-retardant efficiency with the latent heat at 149.9 J/g. Thermal management tests showed that the CPCM had a better temperature control effect than air cooling, especially at high discharge rates. Adiabatic experiments further verified that CPCM had good latent-heat-cooling performance and a positive effect on delaying the occurrence of TR and reducing the risk of TR for battery applications.