Charge Storage Performance of Porous Activated Carbon Derived From Bamboo Stems for Symmetric Supercapacitor Electrodes

Abstract

Activated carbon (AC) obtained from bamboo stems is used in this study as an electrode material for the symmetric supercapacitor as it is cost-effective and bio-renewable. The activated carbon was synthesized in two steps at the optimal temperature of 700°C, involving thermal carbonization and chemical activation with ZnCl₂. The distorted honeycomb and void-containing surface morphology of the synthesized activated carbon (AC_b) was confirmed by scanning electron microscope (SEM) analysis. X-ray diffraction (XRD) was performed for the crystallography, and X-ray photoelectron spectroscopy (XPS) was performed for the elements' chemical states. Brunauer–Emmett–Teller (BET) analysis confirmed the mesoporosity (avg. pore radius 42.1 Å) and high specific surface area (92.1 m² g⁻¹) of the AC_b. Electrochemical studies revealed that the three-electrode system demonstrated a specific capacitance of 75.8 F g⁻¹ at 5 mV s⁻¹ in 1 M NaOH electrolyte. A capacitance retention of 75% was obtained even after 10,000 cyclic voltammetry (CV) cycles. An LED light was illuminated using a fabricated two-electrode symmetric device. However, for practical applications, more durability study is needed. This study offers insightful new information about how to best utilize chemically processed AC derived from bamboo stems in modern energy conservation systems.