Novel hemp biomass-derived activated carbon as cathode material for aqueous zinc-ion hybrid supercapacitors: Synthesis, characterization, and electrochemical performance

This research paper investigates the use of aqueous electrolytes in multivalent zinc-ion hybrid supercapacitors, highlighting their advantages over traditional supercapacitors in terms of increased energy density, cost-effectiveness, and enhanced safety. The study focuses on synthesizing activated carbon materials from hemp biomass through hydrothermal synthesis and KOH chemical activation. The resulting activated carbon possesses a highly porous structure essential for efficient energy storage. Herein, various advanced techniques were employed to examine the structural properties of the activated carbon material, such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) analysis, Fourier-Transform Infrared (FTIR) spectroscopy, Energy-Dispersive X-ray spectroscopy (EDS), and X-ray Photoelectron Spectroscopy (XPS). On the other flip side, the hemp-derived carbon cathode exhibits a high electrochemical capacity of 220 F/g and an energy density of 65 Wh/kg, highlighting its potential for efficient energy storage. Moreover, the cathode material demonstrates remarkable cycling stability, retaining over 98 % of its capacity after 2000 charge/discharge cycles, indicating a promising long cycle life. Overall, this study emphasizes the potential of aqueous electrolytes and hemp biomass-derived carbon materials in advancing the development of high-performance multivalent zinc-ion hybrid supercapacitors.