Interlayer Manipulation for Accelerating Ion Diffusion Kinetics in Ti₃C₂T_X MXene Fiber toward Enhanced...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Polymer incorporation enhances MXene fiber mechanical strength via interfacial cross-linking.
• Improving electrochemical performance (capacitance, rate capability) alongside mechanical strength in MXene fibers is challenging due to sluggish ion diffusion kinetics.

Purpose of the Study:

• To investigate interlayer manipulation in titanium carbide (Ti3C2Tx) fibers using cellulose derivatives.
• To examine the role of substitutional groups in cellulose for optimizing MXene fiber properties.
• To simultaneously enhance mechanical strength and electrochemical performance of MXene fibers.

Main Methods:

• Incorporation of cellulose, specifically hydroxyethyl cellulose (HEC), into MXene dope.
• Analysis of hydrogen bonding between cellulose and Ti3C2Tx nanosheets.
• Evaluation of ion diffusion kinetics and electrochemical performance (capacitance, rate capability) of the modified fibers.

Main Results:

• Cellulose addition improved MXene dope spinnability and bridged Ti3C2Tx nanosheets via hydrogen bonds.
• Hydroxyethyl cellulose (HEC) with optimal group size and adsorption facilitated rapid proton transport by diminishing steric effects.
• Optimized M-HEC-1.0% fiber achieved high capacitance (1531 F cm-3 at 2 A cm-3), enhanced strength (∼76 MPa), and superior rate capability (89.2% retention at 15 A cm-3).

Conclusions:

• Interlayer manipulation using cellulose, particularly HEC, effectively addresses sluggish ion diffusion in MXene fibers.
• The optimized MXene-HEC composite fibers demonstrate a promising balance of mechanical robustness and high electrochemical performance for energy storage applications.