Non-van der Waals superlattices reconcile the strength and conductivity of MXene films

Conventional strategies for assembling macroscopic MXene films require excessive binders, such as polymer chains or cellulose, to bridge adjacent nanosheets, which undermine intrinsic functionalities and reduce MXenes to mere conductive fillers. Here, we present a strategy that leverages the intrinsic structural evolution of MXenes to achieve non-van der Waals superlattice roll-ups, simultaneously enhancing interlayer stress transfer and establishing efficient conductive pathways, thereby overcoming the traditional trade-off between mechanical and electrical performance in MXene films. The resulting scalable high-performance MXene films exhibit remarkable tensile strength (598 MPa) and electrical conductivity (13682 S/cm), while also demonstrating excellent electromagnetic interference shielding. However, a systematic understanding on the reinforcement mechanisms across multiple scales is lacking which limits the rational design of high-performance MXene films. To address this, we systematically elucidate the complex reinforcement mechanisms across multiple scales, from crack deflection at the microscopic level, to dynamic slip and energy dissipation at the nanoscale, and local charge rearrangement through molecular interactions. This work establishes a multiscale blueprint for mechanical enhancement spanning microscopic, nanoscopic, and molecular regimes, representing a significant advance in the development of high-performance films. This study develops non-van der Waals superlattice roll-ups to enhance MXene films, overcoming the strength-conductivity trade-off and revealing multiscale reinforcement mechanisms for advanced multifunctional materials