Modifying nano-silicon with nano-antimony through molten salt electrolysis for superior lithium storage materials

The application of silicon to lithium-ion batteries (LIBs) remains a challenge due to the severe volume expansion effect of silicon. In this work, a nano Si-Sb bimetal is obtained by the molten salt electrolysis of mixture of silicon and antimony sulfide (Sb2S3). The uniform hybrid of antimony nanoparticles not only prevents the agglomeration of silicon but also selectively decomposes the electrolyte additives and alleviates the rupture of SEI effectively, which can mitigate the volume expansion of silicon. When used as a negative electrode for LIBs, the Si-Sb bimetallic electrode delivers a reversible capacity of 1524 mAh/g after 100 cycles at a current density of 1 A/g. Even at 3 A/g, the reversible capacity is as high as 1062 mAh/g after 200 cycles. This work offers a new way for the fabrication of Si-based alloy anodes through using molten salt electrolysis.