The effects of electrospinning parameters on coaxial Sn/C nanofibers: Morphology and lithium storage performance

For tin-based anode materials that suffer from poor cycling stability due to severe volume changes upon lithiation/delithiation processes, the morphology control method might provide a solution. Today, coaxial core-shell structure has attracted wide attention due to its ability to accommodate the volume changes of tin (core), which is well encapsulated in the carbon matrix (shell). Coaxial electrospinning is a simple and effective method to prepare this kind of material. In this work, tin was dispersed in the carbon core and then coated a carbon shell to form Sn@C/C nanofibers by coaxial electrospinning. Flow ratio and tin content were investigated as two main critical factors for controlling the core/shell structure, so as to improve the cycling preference of tin anodes. When tested as a lithium-ion battery anode, the material not only showed higher reversible specific capacity (626 mAh g−1) than pure carbon nanofibers, but also exhibited better cycling performance (50 cycles with 73% capacity retention), indicating that the volume change problem of tin anodes has been well resolved by this morphology control.