MAX Phase Purity Contingent Interlayer Spacing Regulated Ti₃C₂-F MXene Electrodes for Efficient Energy Storage...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Impurity-induced defects in MAX phases negatively impact derived MXene quality.
• These defects disrupt ion transport pathways and hinder electrochemical performance.
• MAX phase purity is a critical factor influencing MXene properties.

Purpose of the Study:

• To systematically investigate the effect of MAX phase purity on MXene quality.
• To understand how impurity-induced defects influence MXene's electrochemical performance.
• To explore strategies for enhancing MXene-based energy storage systems.

Main Methods:

• Synthesis and characterization of MAX phases with varying purity levels.
• Derivation of MXenes from MAX phases and analysis of structural properties.
• Electrochemical testing including galvanostatic charge-discharge (GCD) and cyclic voltammetry.
• Fabrication and evaluation of symmetric battery-type supercapacitor devices.

Main Results:

• Increased MAX phase purity from 47% to 99% led to expanded MXene interlayer spacing.
• Specific capacitance of MXene improved significantly with higher MAX phase purity (121.86 to 680.8 F g⁻¹).
• Incorporation of carbon black (CB) further enhanced specific capacitance to 918.5 F g⁻¹.
• Supercapacitor device demonstrated high specific capacity (76.54 mAh g⁻¹), energy density (55.58 Wh kg⁻¹), and power density (1500.27 kW kg⁻¹).
• Device exhibited excellent cycling stability, retaining 94% capacitance after 5000 cycles.

Conclusions:

• MAX phase purity is crucial for controlling MXene interlayer spacing and electrochemical performance.
• High-purity MAX phases are essential for developing advanced MXene-based energy storage devices.
• This work provides a pathway for designing high-performance hybrid energy storage systems through precise control of precursor material quality.