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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/Ti3C2Tx 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/Ti3C2Tx 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. [ABSTRACT FROM AUTHOR]

The electric double layers (EDLs) at the solid-liquid interface play a significant role in many applications such as batteries, supercapacitors, nano-friction, and capacitive deionization. Molecular dynamics (MD) simulations has become powerful tools for comprehending the microstructure of the EDLs, while their accuracy depends on employed force fields. Herein, we conducted constant potential-based MD simulations with distinct force fields to investigate the EDL structure and its formation. Results indicate that the all-atom force fields meticulously capture the transitions in the EDLs structure from overscreening to crowding. However, the crowding phenomenon is missed by the coarse-grained force field, attributed to its smaller ion volume leading to an underestimation of ion packing. Benefiting from their accuracy in dynamics, force fields that approximately consider polarization effects can precisely predict the charging process of the EDLs. Therefore, we conclude that the all-atom scaled-charge force field is the optimal choice for simulating the structure and formation of the EDLs. This work offers crucial insights into selecting the appropriate force field for future classical MD simulations. [ABSTRACT FROM AUTHOR]