Toward high-performance supercapacitors: Electrodes from solvent-fractionated lignin with enhanced activity

Area of Science:

• Materials Science
• Electrochemistry
• Green Chemistry

Background:

• Lignin's oxygen-rich groups boost supercapacitor potential, but its heterogeneity hinders industrial use.
• Developing sustainable and high-performance electrode materials is crucial for advanced energy storage.

Purpose of the Study:

• To fractionate eucalyptus wood lignin to improve its reactivity and processability.
• To synthesize and evaluate lignin-based phenolic resin-derived carbon materials for supercapacitor applications.
• To optimize the lignin substitution ratio for enhanced electrochemical performance.

Main Methods:

• Solvent extraction and fractionation of eucalyptus wood lignin.
• Synthesis of lignin-based phenolic resin carbon materials with varying lignin substitution.
• Characterization of carbon materials, including specific surface area (BET) and electrochemical performance (capacitance, cycling stability).

Main Results:

• Fractionation reduced lignin's molecular weight and polydispersity, increasing reactivity.
• The optimal material, ALPFC (40% lignin substitution), achieved a high surface area (3210 m²·g⁻¹) and specific capacitance (335.5 F/g).
• ALPFC demonstrated excellent cycling stability (110.88% retention after 10,000 cycles) and dual-electrode performance (98.15% retention).

Conclusions:

• Fractionated lignin is a viable precursor for high-performance supercapacitor electrode materials.
• Lignin-based phenolic resin carbon materials offer a green and efficient alternative to traditional materials.
• This study presents a sustainable approach for lignin valorization in energy storage applications.