Carbon-encapsulated Si nanoparticle composite nanofibers with porous structure as lithium-ion battery anodes

•The porous Si/C composite nanofibers with high Si content can be prepared.•The composite nanofibers could increase the specific capacity of the anode.•The 1D nanofiber structure could stabilize the Si strcture during cycles.•Cells assembled with Si/C nanofibers exhibit good electrochemical performance.

Carbon-coated Si nanoparticle composite nanofibers with porous structure were prepared through a facile electrospinning method. Its structure and morphology were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy, respectively. From emission and transmission electron microscopy results, the Si nanoparticles, around 50 nm in size, were coated by carbon, and then form porous composite nanofibers. The electrochemical properties of the as-prepared composite nanofibers were investigated by galvanostatic charging/discharging, cyclic voltammetry and electrochemical impedance. The results revealed that the composite nanofibers anode could deliver the high capacity of 950 mAh g− 1 after 80 cycles. The excellent cycling performances suggested that the porous composite nanofiber materials could be used as an anode for rechargeable lithium-ion batteries.