Fabrication of free-standing N-doped carbon/TiO2 hierarchical nanofiber films and their application in lithium and sodium storages

To simplify the fabrication of electrode in batteries and improve the electrochemical performance, free-standing films composed of N-doped carbon incorporated TiO2 hierarchical nanofibers were prepared via electrospinning followed by heat-treatment under a nitrogen atmosphere in this study. It is found that hierarchical nanofibers were formed at 700 °C or above due to the phase transformation and the presence of carbon matrix. The as-prepared film was tested as an anode in lithium-ion batteries and sodium-ion batteries. Electrochemical results demonstrate a high rate performance (180 mAh g−1 at 5 A g−1 in lithium ion batteries) and excellent cycle stability can be achieved in lithium-ion batteries as well as in sodium-ion batteries. This self-standing film is binder free and thus promising for scale-up applications for lithium-ion batteries and sodium-ion batteries with easy fabrication and satisfactory electrochemical performance.