Micro-Nano Cavity-Engineered Graphene Phase-Change Composite Film for Bifunctional Thermal Management in Electronics

The growing demands in high-power electronics thermal management necessitate thermal interface materials (TIMs) that synergize high thermal conductivity with efficient temperature-regulation capability. While phase-change materials (PCMs) offer substantial latent heat storage, their inherent low thermal conductivity restricts practical application. To address this challenge, we developed a high-performance phase-change TIM by vacuum-impregnating Tris(hydroxymethyl)aminomethane (Tris) into a structurally engineered three-dimensional graphene micronano-cavity film (GMF), featuring tunable pore architecture and a controlled volumetric-expansion coefficient (VEC) to optimally balance thermal transport and phase-change-induced thermal-energy buffering. The optimized GMF-TIM demonstrated the highest performance of 196.2 J g^-1, anisotropic thermal conductivity (65.5 W m^-1 K^-1 in-plane; 21.9 W m^-1 K^-1 through-plane), and minimized interfacial thermal resistance (0.575 K cm² W^1-). Validated under practical CPU conditions (36 W cm^-2), the GMF-TIM demonstrates an extra ∼8.6 °C temperature reduction compared to commercial TIM counterparts. This study highlights the current GMFs as a transformative solution for next-generation TIMs to resolve critical bottlenecks in advanced electronics thermal management.