MgAl Layered Double Oxide/Reduced Graphene Oxide Composites with Reduced Interfacial Thermal Resistance for Thermal Conductivity and Electrical Insulation Applications

Research and development of polymer composites with high thermal conductivity and excellent electrical insulation are one of the research hotspots in thermal management. Although the thermal conductivity issue has been improved effectively with many methods, it remains challenging due to the interface thermal resistance issues and how to hold the electrical insulation performance at high thermal conductivity. Herein, MgAl layered double oxide/reduced graphene oxide (MgAl-LDO/rGO-s) with a hierarchical structure was innovatively used in the CNF thermal conductivity field. The lamellar structure and strong interfacial interactions between MgAl-LDO and rGO construct the continuous thermal conduction path for phonons transport, and the interface thermal resistance is effectively reduced. Meanwhile, the insulated MgAl-LDO forms a hierarchical structure on the surface of rGO by its positive charge characteristics and keeps excellent electrical insulation properties. Therefore, the CNF/MgAl-LDO/rGO-s composite films exhibit high in-plane thermal conductivity (8.7 W·m–1·K–1), electrical insulation (ρv > 1013 Ω·m), and excellent thermal stability. This work provides an interface engineering strategy for heat conduction and electrical insulation and broadens the upper limit application of thermally conductive polymer composites (TCPC) in thermal management.