Wide Temperature All-Solid-State Ti₃ C₂ T_x Quantum Dots/L-Ti₃ C₂ T_x Fiber Supercapacitor with High Capacitance and...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• MXenes, particularly Ti3C2Tx, are promising 2D materials for energy storage due to their high conductivity and surface area.
• Developing flexible and stable electrodes is crucial for wearable and portable electronic devices.

Purpose of the Study:

• To prepare Ti3C2Tx quantum dots (QDs)/L-Ti3C2Tx fiber electrodes (Q3M7) with enhanced capacitance and flexibility.
• To assemble a wide-temperature, all-solid-state fiber supercapacitor using these electrodes and a novel hydrogel electrolyte.
• To evaluate the electrochemical performance, mechanical strength, and temperature stability of the fabricated supercapacitor.

Main Methods:

• Fabrication of large-size Ti3C2Tx nanosheets (L-Ti3C2Tx) via sedimentation, etching, and delamination.
• Preparation of Ti3C2Tx QDs using an ultrasound method.
• Wet spinning of Q3M7 fiber electrodes.
• Assembly of an all-solid-state supercapacitor using Q3M7 electrodes and a delaminated montmorillonite (F-MMT)/Polyvinyl alcohol (PVA) dimethyl sulfoxide (DMSO) flexible hydrogel (DHGE).

Main Results:

• The Q3M7 fiber electrode exhibited a specific capacitance of 1560 F cm-3 and mechanical strength of 130 MPa.
• The assembled supercapacitor showed a volume specific capacitance of 413 F cm-3 at 0.5 A cm-3.
• The device maintained 97% capacitance after 10,000 cycles and operated effectively from -40 to 60 °C, with an energy density of 36.7 mWh cm-3.
• Excellent flexibility and capacitance retention were observed across the wide temperature range.

Conclusions:

• The developed Ti3C2Tx QD/L-Ti3C2Tx fiber electrode strategy is effective for creating high-performance, flexible supercapacitors.
• The all-solid-state fiber supercapacitor demonstrates excellent electrochemical properties and mechanical stability over a broad temperature range.
• This work offers a viable pathway for designing advanced energy storage devices for demanding applications.