文摘
The effects of 10 wt.% super P carbon, multiwalled carbon nanotubes (MWCNTs), and reduced graphene oxide (rGO) on particles size and electrochemical properties of Na3V2O2x(PO4)2F3-2x cathode material were studied. Among these three carbon polymorphs, using MWCNT in composite is effective to obtain low particle size and enhanced electrochemical properties of Na3V2O2x(PO4)2F3-2x. While using rGO to make the composite, the particle size becomes quite big, leading a smaller surface contact area with the electrolytes and thereby resulting in poor cyclability. Na3V2O2x(PO4)2F3-2x-MWCNT composite shows a high capacity of 98 mAh g−1at 0.1 C rate for 100 cycles, and further, it exhibits a stable capacity of 89 mAh g−1 at 0.2 C rate vs. NaTi2(PO4)3-MWCNT in full cell configuration.