Highly Thermally Conductive and Flexible Thermal Interface Materials with Aligned Graphene Lamella Frameworks

Highly thermally conductive and flexible thermal interface materials (TIMs) are desirable for heat dissipation in modern electronic devices. Here, we fabricated a high-crystalline aligned graphene lamella framework (AGLF) with precisely controlled lamella thickness, pore structure, and excellent intergraphene contact by manipulating the thermal expansion behavior of scanning centrifugal casted graphene oxide films. The rational design of the AGLF balances the trade-off between the thermal conductivity and flexibility of TIMs. The AGLF-based TIM (AGLF-TIM) shows a record thermal conductivity of 196.3 W m^-1 K^-1 with a graphene loading of only 9.4 vol %, which is about 4 times higher than those of reported TIMs at a similar graphene loading. Meanwhile, good flexibility remains comparable to that of commercial TIMs. As a result, an LED device achieves an additional temperature decrease of ∼8 °C with the use of AGLF-TIM compared to high-performance commercial TIMs. This work offers a strategy for the controlled fabrication of graphene macrostructures, showing the potential use of graphene as filler frameworks in thermal management.