Coaxially Integrating TiO 2 /MoO 3 into Carbon Nanofibers via Electrospinning towards Enhanced Lithium Ion Storage Performance

Abstract Conversion‐type transition metal oxide MoO 3 has attracted considerable interest as a promising anode material for lithium ion batteries (LIBs), but it suffers from the low electronic conductivity and the large volume changes upon lithiation/delithiation. To overcome these drawbacks, we herein report the full encapsulation of core‐shelled MoO 3 ‐TiO 2 into the carbon nanofibers (CNFs) via a facile coaxial electrospinning followed by a two‐step annealing process. TiO 2 shells and MoO 3 cores were coaxially integrated into the porous CNFs (denote the composite as TiO 2 /MoO 3 @CNFs). The two‐step annealing strategy (carbonization in Ar and then oxidization in air) allows the readily encapsulation of MoO 3 into CNFs. When applied as anode materials for LIBs, the coaxial TiO 2 /MoO 3 @CNFs demonstrate superior lithium storage performance, delivering a high reversible capacity of 561 mAh/g after 300 cycles at 1000 mA/g with a much higher capacity retention of 70.8% than that of the MoO 3 @CNFs without TiO 2 layers (only 42.3%). The results clearly demonstrate that the CNFs matrices and the TiO 2 shells together efficiently enhance the electrode conductivity and buffer the volume changes of MoO 3 upon cycling.