Biobased Nano Porous Active Carbon Fibers for High-Performance Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Activated carbon fibers (ACFs) are crucial electrode materials for supercapacitors.
• Tailoring pore structure in ACFs is key to enhancing their electrochemical performance.
• Wood sawdust offers a sustainable precursor for ACF production.

Purpose of the Study:

• To investigate the impact of KOH activation parameters on ACF pore structure.
• To correlate ACF morphology and pore characteristics with electrochemical properties.
• To optimize ACF synthesis for high-performance supercapacitor electrodes.

Main Methods:

• ACFs were synthesized from wood sawdust using the KOH activation method.
• Activation parameters including temperature, KOH/fiber ratio, and time were systematically varied.
• ACF morphology, pore structure, and electrochemical performance (capacitance, rate capability, cycling stability) were analyzed.

Main Results:

• Activation temperature significantly influenced ultramicropore formation (<0.6 nm), crucial for capacitance.
• Temperatures above 800 °C promoted the generation of 0.8- and 1.1-nm micropores.
• Increased KOH/fiber ratio and activation time led to micropore enlargement into the mesoporous range (2-5 nm).
• Optimal ACF synthesis resulted in a specific capacitance of 225 F/g at 0.5 A/g.
• The optimized material demonstrated 85.3% capacitance retention at 10 A/g and excellent cycling stability (94.2% retention after 10,000 cycles).

Conclusions:

• KOH activation parameters critically control ACF pore structure and supercapacitor performance.
• Optimized ACFs exhibit high specific capacitance and superior rate capability.
• These wood-derived ACFs show outstanding electrochemical stability, positioning them as promising electrode materials for energy storage applications.