Tin/tin antimonide alloy nanoparticles embedded in electrospun porous carbon fibers as anode materials for lithium-ion batteries

The pulverization of Sn-based electrode materials, caused by the large volume effect during the charging/discharging process, seriously affects their battery life. Compounding electrospun carbon fibers with a porous structure is an effective means of solving this problem. In this work, porous carbon nanofibers (PCNFs) containing Sn and tin antimonide (SnSb) alloy nanoparticles are prepared by electrospinning using self-made highly dispersed Sb–SnO2 (denoted as antimony-doped tin oxide) wet gel as the precursor of Sn and Sb and polyacrylonitrile (PAN) and polyvinylpyrrolidone (PVP) as the carbon sources. The porous structure is constructed using the difference in solubility in water between PAN and PVP. The results indicate that the as-fabricated PCNFs have a large number of pore structures and an even distribution of Sn and SnSb alloy nanoparticles, which are conducive to an increase in the content of Sn–SnSb electrode active materials. The porous structure both increases the specific surface area of the electrode material and effectively alleviates volume change. Therefore, the as-fabricated Sn–SnSb/PCNFs exhibit high specific capacities and outstanding rate performance and cycling retention, delivering specific capacities of 922 mAh g−1 and 266 mAh g at 50 mA g−1 and 5 A g−1, respectively, as well as a high cycle stability (71%) for 600 cycles at 1 A g−1. This demonstrates their potential application as anode materials in high-energy-density lithium-ion batteries.