Engineering iron sulfide/carbon co-coated silicon nanoparticles as a lithium-ion battery anode displaying stable capacity and rate-performance

Abstract

Engineering optimal Si-based composites is critical for advancing Li-ion battery technology. Here, we develop iron sulfide (FeS) and carbon co-coated Si (Si@FeS/C) as a high-performance anode. The Si@FeS/C structure reduces the formation of a non-stable solid electrolyte interface, enabling good capacity and stability. The Si@FeS/C anode maintains a stable capacity of 809 mA h g⁻¹ at 0.1 A g⁻¹ along with a coulombic efficiency of 98% after 50 cycles and displays a capacity of 669 mA h g⁻¹ after 100 cycles at 0.2 A g⁻¹. In addition, it demonstrates good stability at 50 °C. These findings provide a potential strategy for engineering coatings on Si to achieve high performance.