Vacuum-Filtered MXene/Carbon Nanotube Composite Films for Li-Ion Capacitors

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• MXene materials offer high conductivity and capacitance for energy storage.
• MXene's 2D structure is advantageous but prone to restacking.
• Carbon nanotubes (CNTs) can enhance material stability and conductivity.

Purpose of the Study:

• To create MXene/CNT composite films for Li-ion capacitors.
• To investigate the role of CNTs in mitigating MXene restacking.
• To evaluate the electrochemical performance of the fabricated Li-ion capacitor.

Main Methods:

• Vacuum filtration to prepare MXene/CNT composite films.
• Physicochemical characterization of the films.
• Electrochemical evaluation in half-cells and a full Li-ion capacitor device.

Main Results:

• MXene/CNT films were successfully prepared, with CNTs preventing MXene flake restacking.
• The Li-ion capacitor achieved a specific capacitance of 26 F g^-1.
• The device exhibited an energy density of 40.2 Wh kg^-1 and power density of 375 W kg^-1.

Conclusions:

• MXene/CNT composite films are viable for Li-ion capacitors.
• CNTs improve structural integrity and performance.
• Further improvements are needed to address ion transport limitations in the layered architecture.