Investigation of Different Aqueous Electrolytes for Biomass-Derived Activated Carbon-Based Supercapacitors

The present work reports the synthesis of biomass derived activated carbon and its electrochemical behaviour in different electrolytes. Ricinus communis shell (RCS) was used as a raw material in this study for the synthesis of activated carbon (AC) following a high-temperature activation procedure using potassium hydroxide as the activating agent. The physical and structural characterization of the prepared Ricinus communis shell-derived activated carbon (RCS-AC) was carried by Brunauer-Emmett-Teller analysis, X-ray diffraction analysis, Fourier Transform Infrared Spectroscopy, Raman Spectroscopy and Scanning Electron Microscopy. The synthesized AC was electrochemically characterized using various techniques such as Cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) tests, and Electrochemical impedance spectroscopy (EIS) measurements in different aqueous electrolytes (KOH, H2SO4, and Na2SO4). The results show that the double layer properties of the RCS-AC material in different electrolytes are distinct. In specific, the working electrode tested in 3 M KOH showed excellent electrochemical performance. It demonstrated a specific capacitance of 137 F g(-1) (at 1 A g(-1) in 3 M KOH) and exhibited high energy and power densities of 18.2 W hkg(-1) and 663.4 W kg(-1), respectively. The observed capacitance in 3 M KOH remains stable with 97.2% even after 5000 continuous charge and discharge cycles, indicating long-term stability. The study confirmed that the synthesized RCS-derived activated carbon (RCS-AC) exhibits good stability and physicochemical characteristics, making them commercially promising and appropriate for energy storage applications.

Automated summary

This study focuses on the synthesis of biomass derived activated carbon and its electrochemical behavior in different electrolytes. The specific capacitance, energy density, and power density of the synthesized activated carbon material were characterized in various aqueous electrolytes. The results showed that the RCS-AC material exhibited excellent electrochemical performance in 3 M KOH, with a specific capacitance of 137 F g(-1), energy density of 18.2 W hkg(-1), and power density of 663.4 W kg(-1). The stability of the capacitance in 3 M KOH was maintained at 97.2% after 5000 continuous charge and discharge cycles, indicating long-term stability. The study concluded that the synthesized RCS-derived activated carbon has promising commercial applications in energy storage.