The Preparation and Capacitance Performance of the K₂FeO₄-activated Biomass Porous Carbon

Graphitic shaddock peel porous carbon (GSPC) was prepared via acombination of K₂FeO₄ soaking treatments and calcination. The morphology and composition of GSPC were studied with the scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy (Raman), and its capacitance performance was studied with cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and the galvanostatic charge-discharge experiment (GCD). The results showed that after the graphitization the BET surface area of porous carbon increased from 75.91 m²/g to 619.78 m²/g, and the pore volume increased from 0.192 cm³/g to 0.425 cm³/g. The GSPC electrode demonstrated a much higher specific capacitance of 245 F/cm² at a current density of 1 A/g and excellent rate capability with the capacitance retention of 74% at the current density of 7 A/g. Moreover, the GSPC electrode also exhibited excellent cycle stability with no capacitance attenuation after 10 000 cycles. This work provides a new path for the explorer of low-cost and high-performance biomass porous carbon.