Optimization of Carbonization Temperature in Mangrove Charcoal-Derived Hard Carbon for High-Performance Sodium-Ion Battery Anodes

Abstract

Owing to the abundant availability of sodium resources, sodium-ion batteries (SIBs) are emerging as a promising alternative to lithium-ion batteries, which rely on raw material resources with a limited supply. In this study, we report the use of hard carbon (HC) derived from mangrove charcoal as a potential anode material for SIBs. Biomass-derived materials, such as mangrove charcoal, are increasingly being recognized as ideal precursors for HC production owing to their renewability and natural abundance. Here, HC was synthesized from mangrove charcoal at various carbonization temperatures to evaluate the effects of thermal treatment on its structural and electrochemical properties. While higher carbonization temperatures generally enhanced the electrochemical performance by improving the crystallinity and reducing the surface defects, oxygen-containing functional groups, and specific surface area, excessively high temperatures deteriorated the electrochemical performance. Among the samples, those carbonized at 1200 °C demonstrated an initial coulombic efficiency of 75% and a reversible capacity of 266.6 mAh/g. Moreover, these samples maintained a high retention capacity of 80.1% after 200 cycles. These results highlight the potential of temperature-optimized mangrove charcoal-derived HC as a high-performance, low-cost, and environmentally friendly anode material for next-generation SIBs.

Keywords: Mangrove Charcoal, Hard carbon, Carbonization Temperature, Sodium-Ion Battery Anodes