Advanced Core-Shell Hollow Carbon Nanofibers for Ion and Electron Accessibility in Sodium Ion Batteries

Abstract

One-dimensional core-shell hollow carbon nanofibers (HCNFs) have been synthesized by coaxial electrospinning, deacetylation and carbonization, which exhibit multi-surface properties that enhance electrolyte infiltration and facilitate ions/electrons transport. The nitrogen-doped hard carbon outer shell compensates for the low conductivity of amorphous carbon, and the inner core carbon supports the stability of core-shell hollow structures. Such unique structure ensures the accessibility of electrons/ions during electrochemical reactions and contributes to the superior rate performance of HCNFs. Ultimately, a high retention rate of 77% of the initial value (0.1 A g–1) capacity was demonstrated at a current density of 2 A g–1. The core-shell hollow structure designed in this work greatly optimizes the sodium transport dynamics.