Biomass-Derived Porous Carbons Derived from Soybean Residues for High Performance Solid State Supercapacitors.

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Developing sustainable energy storage materials is crucial.
• Biomass-derived porous carbons offer a promising alternative to traditional materials.
• Soybean residues present an abundant and underutilized feedstock.

Purpose of the Study:

• To synthesize heteroatom-containing porous carbons from soybean residues.
• To investigate the impact of feedstock concentration on material properties.
• To evaluate the electrochemical performance of these materials in supercapacitors.

Main Methods:

• Hydrothermal treatment, chemical activation, and carbonization processes were employed.
• Soybean residue concentration was varied to optimize material characteristics.
• Electrochemical performance was assessed using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy.

Main Results:

• Biomass-derived porous carbons (BDPCs) with high surface area (up to 1945 m² g⁻¹) and hierarchical porosity were successfully synthesized.
• The SRAC5 sample, derived from a specific soybean residue concentration, showed optimal properties including high nitrogen (3.8 at %) and oxygen (15.8 at %) content.
• The SRAC5 material achieved a specific capacitance of 489 F g⁻¹ in an aqueous electrolyte and a solid-state symmetric supercapacitor (SSC) delivered 123 F g⁻¹ at 1 A g⁻¹ with high energy density (68.2 Wh kg⁻¹) and excellent cycling stability (>89% over 5000 cycles).

Conclusions:

• Soybean residue concentration significantly influences the properties and performance of BDPCs.
• The optimized BDPCs demonstrate excellent potential for high-performance supercapacitor applications.
• The synergistic effects of high surface area, hierarchical pores, heteroatom doping, and electrolyte choice contribute to superior energy storage capabilities.