Deashing Strategy on Biomass Carbon for Achieving High-Performance Full-Supercapacitor Electrodes

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Biomass-derived porous carbons are promising electrode materials for energy storage devices.
• Developing high-performance and cost-effective supercapacitors is crucial for renewable energy integration.

Purpose of the Study:

• To synthesize and characterize novel porous carbon materials from various biomass precursors.
• To investigate the electrochemical performance of these carbons as negative electrodes in asymmetric supercapacitors.
• To optimize carbon electrode performance through deashing and doping strategies.

Main Methods:

• Synthesis of porous carbons (MC, PC, SC) from mushroom dreg, Chinese parasol leaves, and Siraitia grosvenorii leaves at 700-800 °C.
• Fabrication of asymmetric supercapacitors using biomass-derived carbons and Ni(OH)2 or MnO2 modified electrodes.
• Electrochemical characterization including specific capacitance, energy density, and power density measurements.
• Deashing treatments (H2O, HF, mixed acid) and MnO2 doping for performance enhancement.

Main Results:

• SC700 carbon electrode achieved a specific capacitance of 169.5 F g-1, nearly double that of commercial activated carbon.
• SC700//Ni(OH)2 asymmetric supercapacitor demonstrated 80 F g-1 capacitance and 32.16 Wh kg-1 energy density.
• Deashing and MnO2 doping of MC700 electrodes significantly enhanced capacitance and cyclic stability.
• Optimized asymmetric supercapacitors achieved 21.08 Wh kg-1 energy density and 1150 W kg-1 power density, powering 28 LEDs for 5 minutes.

Conclusions:

• Biomass-derived porous carbons, particularly SC700, offer excellent potential for supercapacitor applications.
• Deashing and doping are effective strategies to improve the electrochemical performance of biomass-derived carbon electrodes.
• These enhanced materials pave the way for high-performance, sustainable energy storage solutions.