Constructing Non‐Commensurate Cu–C Interfaces With High Thermal Conductance via Symmetric Tilt Grain Boundaries

ABSTRACT Copper–carbon (Cu–C) composites have achieved great success in various fields owing to the greatly improved electrical properties compared to pure Cu, for example, a two‐order‐of‐magnitude increase in current‐carrying capacity (ampacity). However, the frequent fuse failure caused by the poor thermal transport at the Cu–C heterointerface is still the main factor affecting the ampacity. In this study, we unconventionally leverage atomic distortion at Cu grain boundaries to alter the local atomic environments, thereby placing a premium on noticeable enhancement of phonon coupling at the Cu–C heterointerface. Without introducing any additional materials, interfacial thermal transport can be regulated solely through rational microstructural design. This new strategy effectively improves the interfacial thermal conductance by three‐fold, reaching the state‐of‐the‐art level in van der Waals (vdW) interface regulation. It can be an innovative strategy for interfacial thermal management by turning the detrimental grain boundaries into a beneficial thermal transport accelerator.