N-Doped Carbon Nanofibers with Interweaved Nanochannels for High-Performance Sodium-Ion Storage

Small. 2019 Nov;15(46):e1904054. doi: 10.1002/smll.201904054. Epub 2019 Sep 24.

Abstract

Although graphite materials have been applied as commercial anodes in lithium-ion batteries (LIBs), there still remain abundant spaces in the development of carbon-based anode materials for sodium-ion batteries (SIBs). Herein, an electrospinning route is reported to fabricate nitrogen-doped carbon nanofibers with interweaved nanochannels (NCNFs-IWNC) that contain robust interconnected 1D porous channels, produced by removal of a Te nanowire template that is coelectrospun within carbon nanofibers during the electrospinning process. The NCNFs-IWNC features favorable properties, including a conductive 1D interconnected porous structure, a large specific surface area, expanded interlayer graphite-like spacing, enriched N-doped defects and active sites, toward rapid access and transport of electrolyte and electron/sodium ions. Systematic electrochemical studies indicate that the NCNFs-IWNC exhibits an impressively high rate capability, delivering a capacity of 148 mA h g-1 at current density of as high as 10 A g-1 , and has an attractively stable performance over 5000 cycles. The practical application of the as-designed NCNFs-IWNC for a full SIBs cell is further verified by coupling the NCNFs-IWNC anode with a FeFe(CN)6 cathode, which displays a desirable cycle performance, maintaining acapacity of 97 mA h g-1 over 100 cycles.

Keywords: anodes; carbon nanofibers; electrospinning; interweaved nanochannels; sodium-ion batteries.