Multifunctional load-bearing SWCNT/conjugated polymer composites via covalent interfacial engineering for structural energy materials

Abstract The development of structural energy materials that simultaneously integrate mechanical robustness and energy storage capability remains a critical challenge for next-generation lightweight systems. Here, we report a multifunctional load-bearing composite platform based on single-walled carbon nanotubes (SWCNTs) and conjugated polymers (CPs), achieved via covalent interfacial engineering through azide-induced crosslinking. The CPs conformally wrap SWCNTs through strong π–π interactions, forming a homogeneous fibrous network, while subsequent crosslinking introduces robust interfacial bonding without disrupting the intrinsic electrical properties of SWCNTs. As a result, the optimized composite exhibits a high Young’s modulus of 24 GPa, tensile strength exceeding 220 MPa, and electrical conductivity of 688 S·cm⁻¹, demonstrating a rare combination of mechanical robustness and electrical performance. Importantly, the composite functions as a load-bearing energy storage material, maintaining stable electrochemical performance under mechanical deformation. The synergistic interplay between interfacial bonding, network connectivity, and charge transport is systematically elucidated through morphological, spectroscopic, and nanoscale electrical analyses. This work establishes a general strategy for designing multifunctional hybrid composites that bridge structural and energy functionalities, providing a promising platform for structural energy materials.