Abstract: Interface issues have consistently impeded efforts to balance a trade-offbetween the conductivity func-tionality and mechanical properties of Cu-matrix composites. Combining first-principles simulations, this study addresses this challenge by preparing a new Cu-matrix composite reinforced with MXene, Cu/Ag@MXene composite block (CuAM-CB), which improves the compatibility between metallic Cu and nonmetallic MXene facilitated by Ag modification anchored in situ onto MXene nanosheets, thus realiz-ing element-coupled reinforcement of Ag at the Cu/MXene heterointerfaces. Benefiting from the strong interaction between Ag and C atoms from in situ self-reduction, as well as the excellent compatibility be-tween Ag and Cu atoms (both IB group metals), Ag atoms act as a mediator for the electron transport and mechanical connection at the Cu/MXene heterointerfaces, enabling CuAM-CB to achieve integrated high conductivity functionality (up to 95 % IACS) and strong mechanical properties (with a strength-plasticity product of ∼18 GPa %).

Key words: Cu-matrix composites, MXene, Element-coupled heterointerfaces, High conductivity functionality, Strong mechanical properties