Core–shell structured Na3V2(PO4)3/C nanocrystals embedded in multi-walled carbon nanotubes: A high-performance cathode for sodium-ion batteries

•MWCNT-modified Na3V2(PO4)3/C has been successfully prepared.•The 3D conductive structure is helpful for the performance of the electrode.•The electrode exhibits superior capacity and cycle stability.

In this work, we study the synthesis and electrochemical performance of Na3V2(PO4)3/C and multi-walled carbon nanotubes (MWCNTs) hybrid nanocomposite for use as cathode material in high performance sodium-ion batteries. This nanostructured hybrid material is prepared through a hydrothermal-assisted sol–gel process followed by thermal annealing. The obtained sample has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectrum. The crosslinked MWCNTs can provide good electronic conductive pathways interconnecting Na3V2(PO4)3/C particles. Electrode fabricated from this hybrid material delivers a high reversible capacity and superior rate performance up to an extremely high rate of 10 C. Moreover, ultralong cycling stability is also attained through 500 cycles at 10 C with 93.9% capacity retention. These results demonstrate that the addition of MWCNTs is an effective way to improve the electrochemical performance of Na3V2(PO4)3/C cathode material for sodium-ion batteries.