Sodium Titanate/Carbon ( Na 2 Ti 3 O 7 /C) Nanofibers via Electrospinning Technique as the Anode of Sodium‐ion Batteries

To overcome the sluggish kinetics in sodium‐ion batteries, sodium titanate/carbon ( Na 2 Ti 3 O 7 /C) composite nanofibers as anode materials have successfully been synthesized via a simple electrospinning method. After calcination at 800 °C for 3 h, the obtained Na 2 Ti 3 O 7 nanoparticles are randomly dispersed in the matrix of in situ pyrolized carbon nanofiber. The Na 2 Ti 3 O 7 /C hybrid nanofiber obtained with 2.5 wt% of poly (vinylpyrrolidone) additive in the precursor solution has the smallest diameter of ~120 nm and the finest particle size of ~40 nm, exhibiting the best rate performance of 101 mAh •g −1 at 4 C and excellent capacity retention of 82% at 1 C after 100 cycles. Furthermore, this composite nanofiber also demonstrates good cycling performance under low current density of 0.1 C, which is attributed to the formation of stable solid electrolyte interface ( SEI ) film induced by small volume expansion/contraction of the fine Na 2 Ti 3 O 7 nanoparticles during the charge/discharge process.