Synthesis of graphitic carbon from empty palm oil fruit bunches through single-step graphitization process using K2FeO4-KOH catalyst as lithium ion battery anode

• Empty palm oil fruit bunches can be utilized as cheap and renewable carbon source. • The single-step K₂FeO₄-KOH impregnation-activation method effectively enhances the graphitization of EPOFB-derived carbon. • Increasing the mass of K₂FeO₄ up to the optimal level, enhances the degree of graphitization. • Electrochemical testing in this research revealed the potential for graphitic biomass from EPOFB as an anode. This research aims to optimize the graphitization process of carbon derived from Empty Palm Oil Fruit Bunches (EPOFB), a renewable biomass source, using a single-step K₂FeO₄-KOH impregnation-activation method. The results demonstrate that increasing the mass of K₂FeO₄, up to the optimal level, enhances the degree of graphitization, as confirmed by XRD and Raman spectroscopy. Optimal performance is observed with a catalyst mass of 0.11 g K₂FeO₄ in the C_ K₂FeO₄(0.11)KOH_800 sample, which exhibits a d 002 spacing of 0.3356 nm, an IG/ID ratio of 2.42, a high surface area of 787.767 m²/g, and clearly defined graphitic layers in TEM images. Electrochemical testing of C_ K₂FeO₄(0.11)_KOH_800 reveals promising results, including the lowest charge transfer resistance (Rct) of 87.18 Ω, a significant area under the curve in cyclic voltammetry, a charging capacity of 330.3 mAh g⁻¹ at 0.1 C, with an excellent rate capability of 183 mAh g⁻¹ at 1 C after 100 cycles, maintaining a retention rate of 68.2 %. The single-step K₂FeO₄-KOH impregnation-activation method effectively enhances the graphitization of EPOFB-derived carbon, offering potential applications in high-performance lithium battery anodes.