Research on the high thermal conductivity composite phase change materials with graphite nanosheets for battery thermal safety

Composite phase change material (CPCM) as an efficient battery thermal management strategy has been widely utilized owing to its promising performance, but its thermal conductivity and stability still need to be improved in battery module. Herein, three different kinds of CPCM have been successfully prepared and utilized in battery module, which are composite with PEG, epoxy resin (ER), silver nanoparticles (AgNP) modified with dopamine hydrochloride (PDA) self-assembled on the surface of graphite nanosheets (GNS), denoted as PEE (PEG/ER), PEG (PEG/ER/GNS), and PEGA (PEG/ER/GNS/Ag), respectively. Among them, the AgNP with super-high thermal conductivity has been distributed on the surface of GNS to form laminated nanostructures, promoting the con-struction of thermal conduction network. The thermal conductivity and latent heat of CPCM are 3.1 W center dot m 1 center dot K 1 and 105.8 J center dot g 1, respectively. Furthermore, even under 35 degrees C ambient temperature, the application of PEGA for battery module can effectively control the maximum temperature below 52 degrees C and maintained a temperature difference within 6 degrees C at a 3C discharge rate, which is better than those of battery modules with PEE and PEG. It reveals that the battery module with designed high thermal conductivity CPCM can provide insights into the passive thermal management and other energy storage fields.

Automated summary

In this study, three different types of composite phase change materials (CPCM) were successfully prepared and applied in battery modules, including combinations with polyethylene glycol (PEG), epoxy resin (ER), and silver nanoparticles (AgNP) modified with dopamine hydrochloride (PDA) self-assembled on the surface of graphite nanosheets (GNS). The addition of AgNP with high thermal conductivity promoted the formation of a thermal conduction network. The thermal conductivity and latent heat of the CPCM were measured to be 3.1 W·m-1·K-1 and 105.8 J·g-1, respectively. The application of the CPCM (PEG/ER/GNS/Ag) effectively controlled the maximum temperature below 52℃ and maintained a temperature difference within 6℃ at a 3C discharge rate, outperforming the modules with PEG and epoxy resin alone. This study provides valuable insights into passive thermal management and other energy storage fields.