Three-dimensional EG@MOF matrix composite phase change materials for high efficiency battery cooling

Abstract

Aiming at the problems of irreversible decay and shortened life of the battery caused by high temperature during the operation of power battery pack, a novel composite phase change material based on metal-organic framework (MOF) was proposed in this work. MIL-101-NH2, an amino functionalized MOF material, was grown in situ on expanded graphite (EG) to synthesize hierarchical structure-based loading material for efficient loading of phase change material lauric acid (LA). The microstructure and structure of the composite phase change materials, thermal properties such as phase change temperature and latent heat, thermal conductivity, thermal stability, thermal cycling properties, as well as thermal stability and thermal cycling properties were tested. The results show that amino functionalization of the loading materials is helpful to further improve the loading rate and latent heat of the composite phase change materials. LA/MIL-101-NH2 and LA/EG@MIL-101-NH2 can be loaded up to 70% and have high phase change latent heat (97.74 J/g and 94.55 J/g). When applied to battery thermal management, LA/EG@MIL-101-NH2 can reduce the battery temperature by 4.5–22.3% under the discharge conditions of 1C, 2C, 3C, 4C and the cycle condition, and keep the safe temperature below 50 °C, which provides a new idea for passive thermal management of batteries.