Wet spinning of MXene (V₂CT_X) based fiber fabric with high electrochemical performance for flexible supercapacitor

Flexible supercapacitor is highly important to future wearable textile electronics and metaverse technologies, yet they are still limited by their unfulfilled specific capacitance and energy density. Here, a MXene (V₂CT_X) based fiber fabric (MFF) was developed via a synergistic flow driven assembly strategy for high-performance supercapacitors. Adapted through reliable approaches of indirect etching, organic cation intercalation, and wet spinning, the MFF presents rich active sites, ordered paths, a moderate specific surface area (41.1 m² g⁻¹), good flexibility and reproducibility. Admirably, the resulting fibrillar meshwork structure was found to be highly conducive to increasing energy density and reducing the electrochemical polarization. In this regard, a relatively good capacitance of 731 F g⁻¹ is achieved at a current density of 0.5 A g⁻¹ in H₂SO₄ electrolyte. Furthermore, the assembled asymmetric solid-state supercapacitor (FSC) exhibits high specific capacitance of 401.2 F g⁻¹ at 0.5 A g⁻¹, long cycle stability (5000 cycles) and high mechanical flexibility (5000 bending cycles). Benefiting from this outstanding electrochemical performance, the FSCs using EMIBF₄/PVDF-HFP as electrolyte can be implied as reliable power source to flexible displaying and health monitoring. This work provides a novel MXene (V₂CT_X) based fiber fabric for constructing flexible electrode, promising to open an avenue toward wearable devices.