Microfluidic‐Assembled Covalent Organic Frameworks@Ti₃C₂T_x MXene Vertical Fibers for High‐Performance Electrochemical Supercapacitors

Abstract

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 Ti3C2Tx MXene (VA‐Ti3C2Tx) 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‐Ti3C2Tx@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

High-Performance Electrochemical Actuator under an Ultralow Driving Voltage with a Mixed Electronic–Ionic Conductive Metal–Organic Framework

“…The CV curves display regular rectangular shapes with broad humps (Figure a and Figure S7), indicating the high ionic conductivity of Ni 3 (HITP) 2 -PP-EA. The double layer capacitance was calculated to be 176.3 F·g –1 at a scan rate of 10 mV·s –1 (Figure b), which is near four times higher than that of PP-EA (48.3 F·g –1 ) and comparable with other supercapacitors reported previously. ,− Besides, no shape deformation was observed during the electrochemical measurements, indicating the excellent stability of the actuators, which is crucial for long-term operation. The Nyquist plot of the low-frequency region of Ni 3 (HITP) 2 -PP-EA is almost vertical to the y- axis (Figure c), indicating an ideal capacitance behavior.…”

Integration of MXene and Microfluidics: A Perspective

“…Researchers have devised a solution to this problem by creating hybrid fibers with a predetermined hierarchy through a microfluidic synthesis process. These fibers combine vertically aligned and conductive Ti 3 C 2 T x MXene (VA-Ti 3 C 2 T x ) with interstratified electroactive COFs (covalent organic frameworks), LZU1 (COF-LZU1) . The generated VA-Ti 3 C 2 T x @COF-LZU1 fibers showcase an impressive gravimetric capacitance of 787 F g –1 when assessed in a three-electrode setup.…”

Unleashing Enhanced Energy Density with PANI/NiO/Graphene Nanocomposite in a Symmetric Supercapacitor Device, Powered by the Hybrid PVA/Na2SO4 Electrolyte

“…Each material has its advantages and disadvantages, which can be efficiently harnessed and minimized through the creation of a ternary composite. Numerous researchers have reported that integrating multiple materials with varied textures and charge storage mechanisms improves the overall capacitive behavior, ultimately leading to enhanced supercapacitive performance. − …”