Development of a multifunctional composite phase change material with superior thermal conductivity, stability, and flame retardancy for battery thermal management

Battery thermal management is critical for enhancing battery performance and safety, and phase change materials (PCMs) offer significant benefits by efficiently absorbing, storing, and releasing latent heat to regulate temperature. A multi-purpose composite phase change material (CPCM) developed for use in the thermal management of batteries is the primary focus of this research. The material's focus is on improving thermal conductivity, structural stability, flame retardancy, flexibility, and thermal energy storage. Paraffin serves as the foundation PCM, thermal conductivity is enhanced by expanded graphite and silicon carbide, and the flexible skeleton is made of Styrene-ethylene-butylene-styrene (SEBS). Flame retardants include zinc borate and ammonium polyphosphate (APP). The addition of nano-SiO 2 enhances the flame retardancy of CPCM even further. The findings demonstrate that silicon carbide is not very effective in increasing CPCM's thermal conductivity. The thermal conductivity of CPCM is only enhanced by 0.413 W/(m·K) when the bulk content of silicon carbide is 7 %. The thermal conductivity of the CPCM was substantially enhanced by expanded graphite, on the other hand. A thermal conductivity increase of 17.87, 11.87, and 4.99 times occurs at 15 % expanded graphite, 10 % expanded graphite, and 5 % expanded graphite, respectively. In a favorable correlation with SEBS content, CPCM's flexibility is enhanced. Furthermore, CPCM's thermal stability can be further enhanced by combining SEBS with EG. APP and zinc borate give CPCM fire resistance. When the ratio of boric zinc acid to ammonium polyphosphate is 4:1, the results demonstrate that CPCM exhibits the best flame retardancy. Furthermore, CPCM's flame retardancy can be further enhanced with the addition of nano-SiO 2 . Even with just 2 % nano-SiO 2 added, the flame retardant amount of CPCM can be reduced by 9 % without compromising its effectiveness. Lastly, the thermal management system for the battery took advantage of CPCM. The experimental findings demonstrated that a 7 °C decrease in battery surface temperature was achieved by implementing CPCM. The surface temperature of the battery can be further lowered by 15 °C when CPCM is combined with liquid cooling plates.