Thermally Conductive Ti3C2Tx Fibers with Superior Electrical Conductivity

High-performance Ti₃C₂T_x fibers have garnered significant potential for smart fibers enabled fabrics. Nonetheless, a major challenge hindering their widespread use is the lack of strong interlayer interactions between Ti₃C₂T_x nanosheets within fibers, which restricts their properties. Herein, a versatile strategy is proposed to construct wet-spun Ti₃C₂T_x fibers, in which trace amounts of borate form strong interlayer crosslinking between Ti₃C₂T_x nanosheets to significantly enhance interactions as supported by density functional theory calculations, thereby reducing interlayer spacing, diminishing microscopic voids and promoting orientation of the nanosheets. The resultant Ti₃C₂T_x fibers exhibit exceptional electrical conductivity of 7781 S cm^-1 and mechanical properties, including tensile strength of 188.72 MPa and Young's modulus of 52.42 GPa. Notably, employing equilibrium molecular dynamics simulations, finite element analysis, and cross-wire geometry method, it is revealed that such crosslinking also effectively lowers interfacial thermal resistance and ultimately elevates thermal conductivity of Ti₃C₂T_x fibers to 13 W m^-1 K^-1, marking the first systematic study on thermal conductivity of Ti₃C₂T_x fibers. The simple and efficient interlayer crosslinking enhancement strategy not only enables the construction of thermal conductivity Ti₃C₂T_x fibers with high electrical conductivity for smart textiles, but also offers a scalable approach for assembling other nanomaterials into multifunctional fibers.