Tuning particle and phase formation of Sn/carbon nanofibers composite towards stable lithium-ion storage

Sn is an attractive anodic material for lithium-ion batteries. High-temperature reduction is large-scale technique since most elemental Sn exists in the form of oxides. However, it is still a challenge to fabricate high performance Sn-based anodes with well-dispersed Sn nanoparticles in conductive matrix due to low melting point of Sn and tendency of particle agglomeration . Herein, we systematically investigate the influences of reduction conditions on particle and phase formation of Sn/carbon nanofibers (CNF) from electrospun SnO 2 /polyacrylonitrile. It is shown that the SnO 2 can be reduced to Sn with slight aggregation at low temperature of 500 °C in a reducing atmosphere, but the composites possess poor electronic conductivity . As raising temperature, the grain size of Sn increases accordingly leading to sluggish Li + internal diffusion dynamics. While in an inert atmosphere , the SnO 2 cannot be reduced completely at low temperature until 650 °C. By optimal control, the Sn/CNF–N 2 -700 calcined at 700 °C in N 2 atmosphere presents the best electrochemical Li-ion storage performance among these samples, which delivers a reversible capacity of 932.2 mAh g −1 at 100 mA g −1 and stable cycling life with 760.3 mAh g −1 retention after 200 cycles. This study may provide optimization guidance for industrial manufacture of Sn-based materials.