Direct planting of ultrafine MoO2+δ nanoparticles in carbon nanofibers by electrospinning: self-supported mats as binder-free and long-life anodes for lithium-ion batteries

Abstract

Three-dimensional (3D) interconnected carbon nanofibrous mats containing well-dispersed MoO_2+δ nanocrystals are fabricated through a facile electrospinning route followed by thermal treatment in N₂. The resulting nanostructured monolithic hybrid mat made of C/MoO_2+δ nanofibers exhibits superior Li-storage performances, when evaluated as a free-standing anode material. At a current density of 200 mA g⁻¹, a reversible capacity as high as 876.9 mA h g⁻¹ is achieved after 250 cycles. A capacity of 447.9 mA h g⁻¹ could still be maintained after 1000 cycles even at a high current density of 2000 mA g⁻¹, indicating high rate capability and cyclability. The attractive electrochemical performances of the as-obtained 3D C/MoO_2+δ networks may benefit from the synergistic effects of the unique nanoarchitectures and the integrity of the electrodes. Monodispersed MoO_2+δ nanocrystals encapsulated in carbon nanofibers not only provide interfacial storage but also improve the transport kinetics of electrons and lithium ions.