Fe²⁺-crosslinked MXene fibers for multifunctional electronic textile

The increasing demand for multifunctional wearable electronics and intelligent electronic textile systems necessitates advanced functional fibers that integrate mechanical durability, superior conductivity, and adaptive functionalities. Here, a Fe²⁺-crosslinking strategy is employed to engineer structural-functional synergy in Ti₃C₂T_x MXene fibers, through the coordination bridging effect between Fe²⁺ ions and Ti₃C₂T_x surface functional groups. This design enhances interlayer interfacial coupling within the nanosheet framework, yielding highly aligned Ti₃C₂T_x fibers with outstanding mechanical strength (143.7 MPa) and electrical conductivity (2607 S cm^-1), simultaneously. As a result, the fibers exhibit excellent Joule heating effect for wearable thermal management, reaching 122°C within 2 min at 2 V. For energy storage, the as-prepared fibers show remarkable pseudocapacitive charge storage capacity of 1239 F cm^-3, enabling fiber-shaped supercapacitors with a high energy density of 14.12 mWh cm^-3 and peak power density of 6000.41 mW cm^-3, surpassing most previously reported MXene-based fiber devices. When woven into common textiles with programmable mesh architectures, the fabrics provide adjustable electromagnetic interference (EMI) shielding, with effectiveness up to 23.1 dB in a 1×1 cm² grid configuration. This multifunctional Ti₃C₂T_x fiber offers a versatile platform for integrated thermal management, self-powered microsystems, and electromagnetic protection textiles, demonstrating significant potential for next-generation wearable electronics.