Vertically aligned carbon nanotube film/graphene/silicone grease as high-performance thermal interface materials with enhanced thermal conductivity

The continuous advancement of electronic devices towards miniaturization and high integration has led to a rapid increase in power density, making effective heat dissipation a critical challenge. Carbon nanotube films (CNFs) are widely recognized as excellent thermal interface materials (TIMs) due to their exceptional in-plane thermal conductivity. However, the poor through-plane thermal conductivity limits their broader application. In this study, we developed a Vertically Aligned Carbon Nanotube Film/Graphene/Silicone Grease (VCGG) using scalable chemical vapor deposition (CVD) and spray coating techniques. The VCGG exhibits a through-plane thermal conductivity of 15.2 W/(m·K), surpassing conventional silicone greases (e.g., ShinEtsu G-751, λ ~ 4. 5 W/(m·K)) by more than 300 %. When integrated into smartphone thermal management systems, theVCGG reduces the CPU and rear cover temperatures by 4.3 °C and 2.6 °C, respectively, under high-power operation. Mechanistic analysis reveals that the functional groups of graphene oxide adsorb onto the carbon nanotube film, densifying its interlaced hollow network structure and thereby enhancing the thermal conductivity of the composite film. • The VCGG exhibits a through-plane thermal conductivity of 15.2 W/(m·K), surpassing silicone greases by more than 300 %. • Compared to silicone greases, The VCGG could save energy and enhance the battery running time as long as 19 min.