Oriented Assembly and Bridging of 2D Nanosheets Enabled High‐Performance MXene Composite Fiber via Dual‐Spatially Confined Spinning

Abstract Assembling 2D nanosheets into high‐performance fibrous assemblies offers a promising way to develop advanced fibers and textiles. However, the performance of fibrous assemblies far below the intrinsic superiority of individual nanosheet, resulting from disordered arrangement and loosely integration. Herein, high‐performance MXene‐based lightweight conductive fiber with extremely high electrical conductivity and mechanical flexibility is developed, via dual‐scale spatially confined spinning for the coassembly of nanosheets and nanofibers with hierarchical dimensions and shapes into an exceedingly good oriented structure. 2D MXene nanosheets are aligned due to the microscale confined space of microfluidic channel induced by coaxial polymer‐shell, while high‐aspect‐ratio 1D carbon nanofibers are aligned due to the nanoscale confined space between adjacent MXene nanosheets. During the dual‐spatially confined wet‐spinning process, the oriented assembly of MXene nanosheets can regulate carbon nanofibers from disordered curling to highly ordered extending, which induce effective nanoscopic interconnection among MXene nanosheets bridged by nanofibers for tightly integration. Benefiting from precise alignment and tightly bridging via dual‐spatially confined assembly, efficient stress/electron transfer between nanosheets is achieved, resulting in assembled MXene macroscopic fiber owns superior high mechanical strength (506.7 MPa) and electrical conductivity (1.27 × 10 ⁶ S m ⁻¹ ). The dual‐spatially confined wet‐spinning assembly paves the way to orderly assemble nanosheets towards next‐generation advanced fibers and textiles.