Surfactant-assisted synthesis of porous TiO2 nanofibers as an anode material for secondary lithium ion batteries

Abstract

An optimized amount of cetyltrimethylammonium bromide (CTAB) as a surfactant was used for the first time to fabricate porous TiO₂ nanofibers by an electrospinning technique combined with post-annealing at 500 °C for 5 h in air medium. The fabricated porous TiO₂ nanofibers were systematically characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, surface area measurements and electrochemical testing. The porous TiO₂ nanofibers contained numerous surface pores with an average diameter of ∼80–90 nm. As an anode, the porous TiO₂ nanofiber electrode delivered not only a high reversible capacity and excellent cycle stability over 100 cycles but also excellent rate capability at various current rates in comparison to control TiO₂ nanofibers (prepared in the absence of CTAB). The rapid transportation of lithium ions and reduced lithium ion diffusion length probably are responsible for the improved electrochemical performances of the porous TiO₂ nanofiber electrode synthesized in the presence of the CTAB surfactant.