Scalable synthesis of Si/C anode enhanced by FeSix nanoparticles from low-cost ferrosilicon for lithium-ion batteries

Silicon is considered as the most promising anode for advanced lithium-ion batteries (LIBs) due to the high theoretical capacity of 3579 mAh g−1, but the complex and high-cost preparation processes have limited it's widespread applications. So given the practical application, it's all the more important that we should prepare excellent electrochemical performance anodes with large scale and low cost. Here we present a scalable synthesis for preparing the cost-effective Si/C anode enhanced by FeSix nanoparticles (FSC) directly from the low-grade Ferrosilicon source (∼1000 $/t). The formation of the amorphous carbon layer and FeSix nanocrystalline (FeSi & FeSi2) can act as buffer layer to mechanically support the volume expansion change during cycling. The FSC anode exhibits a high initial capacity of 1489 mAh g−1 and a prolonged cycle performance with 86% capacity retention over 100 cycles at 500 mA g−1. Moreover, the FSC anode delivers an excellent rate performance of 450 mAh g−1 at 10 A g−1 due to the enhancement of the electrical conductivity by the amorphous carbon layer and the highly conductive FeSix nanocrystalline. This scalable and cost-effective method for preparing Si/C anode provides the promising application potentials in next generation energy storage systems.