Synthesis and characterization of biomass-derived hard carbon for lithium-ion battery anode in electric vehicle applications

Abstract

Development of sustainable and high-performance hard carbon anode for lithium-ion batteries (LIBs) using rice husk biomass have been performed in this study. The material was synthesized through pyrolytic carbonization followed by potassium hydroxide (KOH) activation to enhance structural and electrochemical properties. Characterization results confirmed the formation of an amorphous turbostratic carbon structure with a defect ratio (I_D/I_G) of 1.05, along with a high specific surface area of 185 m²/g and a pore volume of 0.21 cm³/g, which are significantly improved compared to nonactivated biomass-derived carbons. Electrochemical testing revealed a high initial discharge capacity of 320 mAh/g at 0.1 C, which is comparable to or slightly higher than conventional graphite anodes (~300 mAh/g). The material exhibited excellent cycling stability with over 90% capacity retention after 100 cycles and demonstrated a superior rate capability of 210 mAh/g at 2C, outperforming many reported biomass-derived hard carbons. Overall, improved performance is attributed to the synergistic effect of hierarchical porosity and surface functional groups introduced during activation. These results show that for advanced LIB applications, rice husk-derived hard carbon provides an affordable and scalable substitute for traditional anode materials.