Zn2+-induced MoO₃ quantum dots/Ti₃C₂Tₓ MXene fibers for high-performance fiber-shaped supercapacitors

Fiber-shaped supercapacitors (FSCs) serve as optimal energy storage components in wearable platforms. However, traditional fiber materials suffer from poor interfacial cross-linking, disordered microstructures, insufficient active sites, and low electrical conductivity. To overcome these challenges, this research develops Zn-MoO₃/Ti₃C₂Tₓ hybrid fibers via wet-spinning technology employing glacial acetic acid as a coagulation bath, with MoO₃ quantum dots intercalated into Ti₃C₂Tₓ interlayers and Ti₃C₂Tₓ nanosheets cross-linked by Zn 2+ . The resulting hybrid fibers feature expanded interlayer spacing, a large ion-accessible surface area, abundant porous channels, exceptional electrical conductivity, and excellent mechanical properties, delivering an exceptional volumetric capacitance of 2078.2 F cm −3 at 2 A cm −3 with 75.0 % capacitance retention at 20 A cm −3 . Furthermore, the constructed FSCs achieve a substantial energy density of 55.6 mWh cm −3 at a power density of 400 mW cm −3 , with 94.7 % capacitance retention after 5000 cycles, and successfully power an electronic timer, demonstrating their potential for wearable applications.