Lauric Acid/Expanded Graphite Composite Phase Change Film with High Thermal Conductivity for Thermal Management

Abstract

With the rapid development of electronics toward integration and miniaturization, efficient and accurate removal of excess energy from electronics has become a major challenge. In this study, a novel expanded graphite-based composite phase change film (EL) with high thermal conductivity was synthesized to facilitate the heat dissipation of electronic devices. The expanded graphite was compressed into a thin film and then impregnated with lauric acid (LA) to form EL. The effect of pressure on the thermal performance of EL was investigated. The results show that the latent heat storage capacity of composite phase films increases with the decrease in pressure. The melting and cooling enthalpy of EL-0 reach up to 111.6 and 107.9 J/g, respectively. Meanwhile, the corresponding in-plane thermal conductivity and axial thermal conductivity reach up to 21.28 W/(m•K) and 9.70 W/(m•K), which are 54.6 and 24.9 times those of the pure LA, respectively. It is interesting that the introduction of a phase change material (PCM) improves the axial thermal conductivity in comparison with the expanded graphite film without the PCM. The obtained EL exhibits excellent leakageproof property and long-term thermal reliability. Last, the EL utilized in the thermal management of the graphics processing unit of the laptop running decreased the temperature by 5.0 °C, implying a potential application in the thermal management of electronics.