Utilizing rice husk-derived Si/C composites to enhance energy capacity and cycle sustainability of lithium-ion batteries

Abstract

Traditional graphite anodes have a specific capacity of approximately 372 mAh/g, whereas silicon presents a promising alternative with theoretical capacities reaching up to 4200 mAh/g. However, substantial volumetric changes in silicon during lithiation lead to rapid degradation of capacitance. This study explores the utilization of rice husk, an abundant agricultural waste, as a raw material for Si/C composites. Rice husk inherently contains significant amounts of silicon and carbon, rendering it a sustainable and economical source. The activated carbon was derived from rice husk by carbonization and thermochemically activation with activation temperature of 850 °C and KOH agent. The silicon dioxide was derived from rice husk by subjecting to annealing in a muffle furnace at 650 °C for 4 h following NaOH and HCl solution treatment. The silicon was derived from silicon dioxide by thermomagnesium treatment in a tube furnace at 700 °C for 120 min. SEM, elemental analysis, XRD, Raman, and FT-IR were used to characterize the materials to evaluate their morphological and structural composition. Electrochemical performance evaluation demonstrated improved energy capacity and stability, highlighting rice husk-derived Si/C composites as a viable solution for advancing lithium-ion battery performance. This innovative approach not only lowers production costs but also supports sustainable development by effectively utilizing agricultural waste.