Facile synthesis of FeCO3/nitrogen-doped carbon dot composites for lithium-ion battery anodes

FeCO3 has attracted increasing attention as an anode material for lithium-ion batteries (LIBs) due to its high capacity, abundance and low cost. However, the poor electronic conductivity and slow ion diffusion dynamics of FeCO3 limit its rate performance. To address this issue, a FeCO3/nitrogen-doped carbon dot (FeCO3/N-CD) composite applied in LIBs is developed by a facile one-step hydrothermal method. It is found that the introduction of N-CD effectively inhibits the crystal growth and stacking of FeCO3, leading to the formation of a unique nanorod composite with hierarchical porous structure. Benefiting from the rational structure, the as-prepared FeCO3/N-CD composite shows significantly improved electrochemical performances when used as anode materials of LIBs. For example, a stable reversible capacity of 872 mA h g−1 after 460 cycles at a current density of 200 mA g−1 can be achieved, which is much higher than that of the pristine FeCO3. This study provides an efficient route to prepare advanced FeCO3-based composites for anode materials in high-performance LIBs.