Enhanced Electrochemical Properties of Biobased Activated Carbon for Supercapacitors

Supercapacitors are great candidates for energy boosting, power, and memory backup. However, they suffer from low-energy density, relatively high cost, and carbon footprint problems due to their electrode materials, such as commonly used activated carbons (ACs). To prepare better renewable ACs, 11 biomass materials are pretreated with hydrothermal processing and then activated at high temperature with potassium hydroxide (KOH) in the present study. The prepared ACs are characterized for scanning electron microscopy images, atomic concentration, specific surface areas, electrical conductivity, cyclic voltammograms, and specific capacitance to determine their potential for supercapacitor application. The electrical conductivity reaches 0.47–1.23 S cm⁻¹, and specific capacitance reaches 250–360 F g⁻¹ (at current density 20 A g⁻¹), which are much higher than previously reported literature values (conductivity <0.3 S cm⁻¹, capacitance 40–160 F g⁻¹) for biobased ACs, indicating great potential for supercapacitor application of our biobased ACs.