Activated carbon with graphitic content from stinky bean seedpod biowaste as supercapacitive electrode material

Activated carbon (AC) is a typical material for supercapacitor electrode fabrication and operates in the electrochemical double layer mechanism. Biomass-derived carbon is an attractive precursor of AC synthesis due to its renewable and cost-efficient properties. In this study, stinky bean or Parkia javanica seedpod (PJS) was used to produce AC using a chemical activation method, and the electrochemical properties was carefully investigated. The prepared AC activated at 700 °C (PJC-700) exhibited the optimum edge fraction (0.254), the average number of layer planes in a crystallite (1.935), pore size distribution (1.9 nm) and ID/IG ratio (0.796) properties. The electrode shows specific capacitance of 248 F/g @ 25 mV/s and 193 F/g @ 0.5 A/g in 1 M KOH electrolyte. The AC delivered energy density of 10.58 Wh/kg at power density 720 W/kg in symmetric cell configuration. Moreover, PJC-700 achieved ~ 94% of capacitance retention after 10,000 cycles at 3 A/g current density.