Microfluidic-Assembled Covalent Organic Frameworks@Ti 3 C 2 T x MXene Vertical Fibers for High-Performance Electrochemical Supercapacitors.

The delicate design of innovative and sophisticated fibers with vertical porous skeleton and eminent electrochemical activity to generate directional ionic pathways and good faradic charge accessibility is pivotal but challenging for realizing high-performance fiber-shaped supercapacitors (FSCs). Here, we develop hierarchically ordered hybrid fiber combined vertical-aligned and conductive Ti 3 C 2 T x MXene (VA-Ti 3 C 2 T x ) with interstratified electroactive covalent organic frameworks LZU1 (COF-LZU1) by one-step microfluidic synthesis. Due to the incorporation of vertical channels, abundant redox active sites and large accessible surface area throughout the electrode, the VA-Ti 3 C 2 T x @COF-LZU1 fibers express exceptional gravimetric capacitance of 787 F g -1 in three-electrode system. Additionally, the solid-state asymmetric FSCs deliver prominent energy density of 27 Wh kg -1 , capacitance of 398 F g -1 and cycling life of 20000 cycles. The key to high energy storage ability originates from the decreased ions adsorption energy and ameliorative charge density distribution in vertically aligned and active hybrid fiber, accelerating ions transportation/accommodation and interfacial electrons transfer. Benefiting from excellent electrochemical performance, the FSCs offer sufficient energy supply to power watch, flag and digital display tube as well as be integrated with sensor to detect pulse signals, which opens a promising route for architecting advanced fiber towards carbon neutrality market beyond energy-storage technology. This article is protected by copyright. All rights reserved.