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.