Titanium dioxide (TiO₂) is a promising anode material for lithium-ion batteries (LIBs) owing to its low price, excellent cycling stability, low operating voltage, and environmentally friendly nature. However, owing to their poor electrical and ionic diffusion, TiO₂ anodes show low specific capacity and poor high-rate performance. In this study, in an attempt to improve the electrical and ionic diffusion properties, we dispersed TiO₂ nanoparticles into N- and P-doped carbon nanofibers (N/P-doped CNF/TiO₂) using the hydrothermal, electrospinning, and carbonization processes. The N/P-doped CNF/TiO₂ electrode showed high specific capacity (311.5 mAh g^-1 at 100 mA g^-1 after 100 cycles), outstanding high-rate performance (286 mAh g^-1 at 2000 mA g^-1), and excellent ultrafast cycling stability (285 mAh g^-1 at 2000 mA g^-1 after 500 cycles). The results showed that dispersing TiO₂ nanoparticles into N- and P-doped CNFs is an efficient approach to improve their electrical conductivity, shorten their lithium ion diffusion pathways, and stabilize the electrochemical conditions for ionic diffusion during ultrafast cycling.

Keywords: Lithium-ion batteries, TiO₂ nanoparticles, Carbon nanofibers, Heteroatom doping, Synergistic effect, Ultrafast cycling performance