Ultrafine MoO(2) nanoparticles encapsulated in a hierarchically porous carbon nanofiber film as a high-performance binder-free anode in lithium ion batteries

Flexible free-standing hierarchically porous carbon nanofibers embedded with ultrafine (∼3.5 nm) MoO(2) nanoparticles (denoted as MoO(2)@HPCNFs) have been synthesized by electrospinning and subsequent heat treatment. When evaluated as a binder-free anode in Li-ion batteries, the as-obtained MoO(2)@HPCNFs film exhibits excellent capacity retention with high reversible capacity (≥1055 mA h g(−1) at 100 mA g(−1)) and good rate capability (425 mA h g(−1) at 2000 mA g(−1)), which is much superior to most of the previously reported MoO(2)-based materials. The synergistic effect of uniformly dispersed ultrasmall MoO(2) nanoparticles and a three-dimensionally hierarchical porous conductive network constructed by HPCNFs effectively improve the utilization rate of active materials, enhance the transport of both electrons and Li(+) ions, facilitate the electrolyte penetration, and promote the Li(+) storage kinetics and stability, thus leading to a greatly enhanced electrochemical performance.