Preparation of metal-based microencapsulated phase change material and its application in a battery for thermal management and thermal runaway protection

Abstract

The performance and safety of lithium-ion batteries are significantly affected by temperature, and thermal management and thermal runaway protection are necessary. The temperature ranges of battery thermal management and thermal runaway based on phase change materials (PCMs) are inconsistent. A single organic PCM and hydrated salt PCMs have application limitations. In this article, low temperature phase change microcapsules (MEPCM) with thermal management capabilities and medium temperature MEPCM with thermal runaway protection functions have been innovatively prepared respectively, and the performance of their mixture was studied. The results showed that the latent heat value of low temperature MEPCM was 231.4 J/cm³, indicating high thermal reliability. The latent heat value of the medium temperature MEPCM was 426.1 J/cm³, exhibiting good thermal shock resistance and thermal response characteristic. At an ambient temperature of 35 °C and a discharge rate of 4C, the maximum temperature of the battery based on MEPCM mixture is 54.8 °C. At room temperature, MEPCM mixture delayed the time of thermal runaway by 30 %. After 100 s, the outside temperature of the battery was 68.6 °C, decreasing the heating rate by 81.4 %. The MEPCM mixture possesses flame retardancy and didn't release heat, greatly improving the safety of power battery operation.