Effect of carbonization temperatures on the synthesis of biocarbon from Borassus flabellifer fruit fiber for capacitive energy storage

Borassus flabellifer (Palmyra) fruit fiber (PFF) was extracted and converted into biocarbon materials at different carbonization temperatures of 400°C, 600°C, and 800°C under N₂ atmosphere for 1 h. The physicochemical properties of obtained biocarbon materials were investigated via CHNS, SEM-EDX, FTIR, RAMAN, XRD, BET-specific surface area, and TGA techniques. The obtained results were correlated with the capacitive energy storage application of biocarbon materials. The highest specific surface area of 46.36 m² g⁻¹ was observed for the biocarbon materials obtained at 800°C, which also showed superior capacitive performances. The specific capacitances of PFF-derived biocarbon materials obtained at 400°C, 600°C, and 800°C are respectively found to be 28.58, 37.07, and 45.76 F g⁻¹ at 1 A g⁻¹ employing 1M KOH as electrolyte. The biocarbon materials obtained at 800°C showed the highest specific energy and power of 1.99 and 261 W kg⁻¹ at 1 A g⁻¹.