TiNb2O7 hollow nanofiber anode with superior electrochemical performance in rechargeable lithium ion batteries

Hollow microstructure always exhibits some special properties in the field of electrochemistry . Here, this study reports the rational design and preparation of TiNb 2 O 7 nanofibers with one dimensional hollow structure via co-electrospinning. The as-electrospun TiNb 2 O 7 hollow nanofibers show high intercalation potential, low charge-charge resistance and fast electrochemical kinetics . The electrochemical results exhibit that the TiNb 2 O 7 hollow nanofibers deliver a reversible capacity of 210.1   mAh   g −1 after 150 cycles at a current rate of 0.4   C, and 158.4   mAh   g −1 after 900 cycles even at a current rate of 10   C with an outstanding capacity retention of 80.6%. The excellent electrochemical performance of nanofibers can be related to the unique morphology of hollow structure. Furthermore, the lithium ions storage mechanism of TiNb 2 O 7 hollow nanofibers is also systematically analyzed, which is related to one two-phase coexistence and two solid-solution processes during the whole charge-discharge cycle. In addition, it is also demonstrated by in situ and ex situ observations that TiNb 2 O 7 hollow nanofibers have outstanding structural stability and electrochemical reversibility. Therefore, the TiNb 2 O 7 hollow nanofibers can be applied as an alternative promising electrode material for the next rechargeable lithium ions batteries .