High-performance thermal interface materials enabled by vertical alignment of lightweight and soft graphene foams

High-performance thermal interface materials (TIMs) are highly sought after for modern electronics. Two-dimensional (2D) materials as vertical aligned fillers can optimize the out-plane thermal conductivity (k⊥), but their excessively high content or intrinsic rigidness deteriorate TIMs softness, leading to worsening for thermal contact resistance (Rcontact). In this study, 2D graphene materials are fabricated into lightweight and soft graphene foams (GFs) with high-orientation, acting as vertical filler frameworks to optimize the k⊥ and Rcontact for vertical GF (VGF) TIMs. The VGF-TIM has a high k⊥ of 47.9 W·m−1·K−1 at a low graphene content of 15.5 wt.%. Due to the softness and low filler contents of GFs, the VGF-TIM exhibits a low compressive module (4.2 MPa), demonstrating excellent compressibility. The resulting TIM exhibit a low contact resistance of 24.4 K·mm2·W−1, demonstrating 185.1% higher cooling efficiency in practical heat dissipating scenario compared to commercial advanced TIMs. This work provides guidelines for the design of advanced TIMs and their applications in thermal management.