Structurally oriented black phosphorus/MXene heterostructured fibers for flexible supercapacitors with enhanced ion transport and capacitive charge storage

Abstract

The development of flexible MXene-based fiber supercapacitors (FSCs) with high conductivity and high specific capacitance has become a research hotspot. However, the assembly of nanosheets into macroscopic fibers with a regular arrangement and the phenomenon of nanosheet restacking remain a huge challenge, which limit the practical application of flexible MXene-based FSCs. In this paper, structurally oriented BP/Ti₃C₂T_x heterostructured fibers have been successfully prepared by a wet-spinning process, and their ordered channel shortened the ion transport path. Black phosphorus (BP) in BP/Ti₃C₂T_x can not only effectively prevent the restacking of MXene nanosheets, but also greatly improve the mechanical strength (401 MPa) and electrical conductivity (6019 S cm⁻¹), and achieve a pseudocapacitor charge storage capacity of 383.9 F g⁻¹. In addition, the energy density and power density of FSCs assembled with heterostructured fibers can reach 5.1 mW h g⁻¹ and 175 mW g⁻¹, respectively. This work provides a reference for the development of high-performance flexible MXene-based FSCs.