Centrifugally-spun PVA-based N, S-doped carbon nanofibers

Abstract

Due to their tunable porous structures with small diameters, carbon nanofibers (CNFs) offer a high aspect ratio and a large surface area, which contribute to enhanced electrochemical performance.In response to environmental concerns associated with petroleum-based carbon precursors, CNFs were synthesized using non-petroleum-based, water-soluble polyvinyl alcohol (PVA) via centrifugal spinning, a safer and faster alternative to electrospinning. The PVA nanofibers were carbonized through high-temperature heat treatment and used as anode materials in sodium-ion batteries (SIBs). To enhance sodium storage capacity, nitrogen (N) and sulfur (S) doping were introduced. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed that the centrifugally spun PVA-based N, S co-doped CNFs exhibited homogeneous, highly porous structures with an average fiber diameter of approximately 260 nm.The defects created by N, S co-doping generated abundant active sites, increasing storage space for Na ions and improving capacity and conductivity. Centrifugally-spun PVA-based N, S codoped CNFs demonstrated a high reversible capacity of 260 mAh g⁻¹ after 200 cycles and maintained a capacity of 140 mAh g⁻¹ even after 2800 cycles at a high current rate of 1 A g⁻¹.These results demonstrate that N, S doping synergistically enhances electron transfer, contributing to improved electronic conductivity. The high-performance, environmentally friendly electrode produced in this study shows promise as a sustainable anode material for SIBs, offering an ecofriendly solution to growing energy demands.