Nanostructured anatase TiO2 as anode of high‐performance lithium‐ion batteries

Abstract Nanostructured anatase TiO2 (NSA‐TiO2) was synthesized via electrochemical anodization of pure Ti foils in a fluorine‐containing electrolyte. The synergistic effects of the anodization period (1 and 2 h) and the surface condition of Ti foils (scratched and unscratched) before anodization was investigated. Four nanostructure variants—unscratched 1 h, unscratched 2 h, scratched 1 h, and scratched 2 h with average pore diameters 15 ± 7.4, 10.1 ± 8.5, 7 ± 7.12, and 8.1 ± 3.79 nm, respectively, were fabricated to assess as negative electrodes of high‐performance lithium‐ion batteries (LIBs). The corresponding first cycle discharge capacities of as‐synthesized NSA‐TiO2 exhibited 433, 93.33, 453.33, and 460.0 mAhg−1. LIB with scratched 1 h NSA‐TiO2 as anode exhibited very propitious outcomes. The reversible capacity at a high 1 C current rate was displayed as 100 mAhg−1 even after 400 cycles along with 103.27% coulombic efficiency. The superior electrochemical performances are attributed to its high specific surface area due to its nanoporous structure. These nanoporous structures provide higher contact between electrodes and electrolytes, shortening the diffusion pathways for conductive ions and electrons that ensured faster kinetics. However, scratching operations increased surface area in the final nanostructure while the short anodization period substantially increased the number of pores.