Carbon Dots Enabling High-Performances Sodium-Ion Batteries

Carbon dots (CDs), known for their quantum size, abundant surface functional groups, excellent biocompatibility, and non-toxicity, have emerged as promising candidates for enhancing various advanced rechargeable batteries. Recent research indicates that electrodes based on or modified with CDs in sodium-ion batteries (SIBs) have shown significant improvements in key performance metrics such as Coulombic efficiency, cycle life, and capacity compared to traditional electrodes. Several key impacts of CDs contribute to these enhancements, including increased conductivity due to their conductive graphitized core, rich absorption sites, and excellent dispersity facilitated by abundant surface functional groups. These features accelerate ion transport through interface edges and ion diffusion paths, inhibit electrode material dissolution, buffer electrode material volume expansion, ensure electrode uniformity and stability, and promote the electrochemical reaction process between the electrode and electrolyte. This review summarizes recent developments, challenges, and opportunities in leveraging CDs as additives in SIBs, focusing on their impact on electrolyte properties, electrode materials, and overall battery performance. It provides a comprehensive understanding of the potential of CDs to significantly advance SIB technology.