Fibrous asymmetric supercapacitor based on wet spun MXene/PAN Fiber-derived multichannel porous MXene/CF negatrode and NiCo₂S₄ electrodeposited MXene/CF positrode

Fiber-shaped supercapacitors (FSSCs) are emerging potential power sources for next-generation flexible and wearable miniaturized electronic devices. However, the practical application of FSSCs is hindered by their low energy density due to limited design and constraints in fiber-shaped electrodes production. Herein, a rational design of wet spun MXene (Ti₃C₂T_x)/PAN fibers derived multichannel porous MXene/Carbon Fiber (W-MX/CF) is reported as a negative electrode (negatrode), and ultrathin NiCo₂S₄ electrodeposited W-MX/CF (NiCo₂S₄@W-MX/CF) as a positive electrode (positrode) for the fabrication of an asymmetric FSSC. It demonstrates high areal capacitance from both the negatrode (C_A = 2160 mF cm⁻²) and positrode (C_A = 1421 mF cm⁻²) fabricated from 80 wt% MXene loaded CF (W-MX/CF-4) with optimized multichannel porous features and faradaic NiCo₂S₄ nanosheets arrays grown on W-MX/CF-4. Solid-state fiber-shaped asymmetric supercapacitor was assembled using NiCo₂S₄-13@W-MX-4 and W-MX/CF-4 as positrode and negatrode, respectively, with PVA/KOH as solid electrolyte. The device exhibits a remarkable energy density of 40.70 mWh cm⁻³ at a power density of 301.51 mW cm⁻³, demonstrating an efficient FSSC. The present work shows a novel way to enhance the performance of FSSCs by exploiting synergistic effects between MXene and carbon fiber derived from PAN, prepared by a facile wet-spinning method employing a solvent/non-solvent exchange process.