Sawdust-derived hard carbon as an anode material for sodium-ion batteries

Abstract

The increasing global energy demand and the environmental impact of fossil fuels have necessitated the development of sustainable energy storage systems. Among various alternatives, Sodium-ion batteries (SIB) have emerged as a promising technology for large-scale applications due to the natural abundance, low cost, and wide geographical availability of sodium resources. This research focuses on the synthesis and characterization of Hard Carbon (HC) derived from sawdust as a sustainable anode material for SIBs. The material synthesis involved a multi-step process, where sawdust was pre-treated with sodium hydroxide (NaOH) and hydrochloric acid (HCl), followed by hydrothermal treatment at 180 °C. The resulting precursor was carbonized at three different temperatures: 800 °C, 1000 °C, and 1200 °C to investigate the impact of thermal treatment on the structural and electrochemical properties. The HC 1000 sample demonstrated the best balance of performance, achieving a specific capacity of approximately 105 mAh/g at 0.05C and a superior capacity retention of 95% after 200 cycles at 0.2C. In contrast, HC1200 showed the highest long-term cyclic stability with an exceptional capacity retention of 99% over 200 cycles at 0.2C, although with a lower capacity. This work provides a sustainable pathway for utilizing biomass waste in high-performance energy storage applications. Keywords: Carbonization, Intercalation, Sawdust-derived HC, Electrochemical performance