Pseudocapacitive sodium-ion storage in one-dimensionally structured anatase TiO₂ nanofiber anode for high performance sodium-ion batteries

Nanofibers provide high surface area to volume ratio, vectoral conduction, fast ionic diffusion, and short pathways for sodium ions. Titania nanofibers exhibit excellent electrochemical performance when used for sodium-ion storage. One-dimensional titania nanofiber was synthesized by an electrospinning process as an anode material for high capacity sodium-ion batteries. The electrochemical kinetics of titania nanofiber for sodium-ion storage were examined. Titania nanofiber exhibited pseudocapacitive capacitive properties with high rate performance, giving capacity of 97 mA h g⁻¹ after 1000 cycles with a current density of 1000 mA g⁻¹. Even when current rate returned to the initial current density of 50 mA g⁻¹, titania nanofiber electrode capacity climbed to 206 mA h g⁻¹ again without capacity fading, which indicated good rate performance, superior sodium insertion/extraction reaction, and high reversible capacity.