Electrospun\nThree-Dimensional Mesoporous Silicon Nanofibers\nas an Anode Material for High-Performance Lithium Secondary Batteries

Abstract

Mesoporous silicon nanofibers (m-SiNFs)\nhave been fabricated using\na simple and scalable method via electrospinning and reduction with\nmagnesium. The prepared m-SiNFs have a unique structure in which clusters\nof the primary Si nanoparticles interconnect to form a secondary three-dimensional\nmesoporous structure. Although only a few nanosized primary Si particles\nlead to faster electronic and Li⁺ ion diffusion compared\nto tens of nanosized Si, the secondary nanofiber structure (a few\nmicrometers in length) results in the uniform distribution of the\nnanoparticles, allowing for the easy fabrication of electrodes. Moreover,\nthese m-SiNFs exhibit impressive electrochemical characteristics when\nused as the anode materials in lithium ion batteries (LIBs). These\ninclude a high reversible capacity of 2846.7 mAh g^–1 at a current density of 0.1 A g^–1, a stable capacity\nretention of 89.4% at a 1 C rate (2 A g^–1) for 100\ncycles, and a rate capability of 1214.0 mAh g^–1 (at\n18 C rate for a discharge time of ∼3 min).