Nitrogen-Doped Porous Carbons Derived from Peanut Shells as Efficient Electrodes for High-Performance Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Nitrogen doping of porous carbon materials is crucial for improving electrochemical performance.
• Developing sustainable and high-performance electrode materials for supercapacitors is an active area of research.

Purpose of the Study:

• To synthesize and characterize nitrogen-doped porous carbon from peanut shells for supercapacitor applications.
• To investigate the effect of different nitrogen dopants on the electrochemical properties of the derived carbon material.

Main Methods:

• Peanut shells were used as a precursor for porous carbon synthesis.
• Various nitrogen dopants (melamine, urea, urea phosphate, ammonium dihydrogen phosphate) were employed.
• Electrochemical performance was evaluated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy.

Main Results:

• The optimized PA-1-1 electrode (using ammonium dihydrogen phosphate) exhibited a high N content (3.11%) and specific surface area (602.7 m²/g).
• PA-1-1 demonstrated a high specific capacitance of 208.3 F/g at 1 A/g in 6 M KOH.
• Excellent rate performance (170.0 F/g at 20 A/g) and cycling stability (98.8% retention after 5000 cycles) were achieved.
• A symmetric supercapacitor (PA-1-1//PA-1-1) showed an energy density of 17.7 Wh/kg at a power density of 2467.0 W/kg.

Conclusions:

• Nitrogen-doped porous carbon derived from peanut shells is a promising electrode material for high-performance supercapacitors.
• Ammonium dihydrogen phosphate is an effective dopant for enhancing the electrochemical properties of peanut shell-derived carbon.
• This study provides insights into designing sustainable biochar-based carbon materials from waste for energy storage devices.