Bramble-like NaVMoO6/C nanofibers with remarkable lithium-storage property are fabricated via a simple electrospinning method. The NaVMoO6 nanoparticles with average size of 84 nm are uniformly embedded into the carbon nanofibers at loading of 77.2 wt%. The unique architecture of the resulting nanocomposite has great advantages like enhanced surface-to-volume ratio, reduced ion transport lengths and strengthened electron transfer along the longitudinal direction. As a new-type anode for lithium-ion batteries (LIBs), NaVMoO6/C composite demonstrates a stable capacity of 1013 and 682 mAh g(-1) at the current density of 0.1 and 1 A g(-1), respectively. Furthermore, the structure evolution mechanism during the first discharge process is carefully researched by ex-situ X-ray diffraction and X-ray photoelectron spectroscopy. It is found that the NaVMoO6 crystals begin to change after being embedded with a few equivalent Li+ when discharging to 2.2 V. With the continuous intercalation of Li+ ions, the main crystal form of the electrode is V2O5 at the potential of about 2.0 V. At low potential (approximate to 1.2 V vs. Li/Li+), the formed V2O5 is transformed into LiVO2. In addition, the volume expansion of the NaVMoO6 particles is alleviated due to the confining effect of carbon nanofibers. Consequently, NaVMoO6/C nanofibers demonstrate a high reversible capacity even at high rate. (C) 2021 Elsevier B.V. All rights reserved.
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