Na3V2(PO4)3/C composites as low‐cost and high‐performance cathode materials for sodium‐ion batteries.

Summary: The carbon layer acting as a conductive medium is beneficial to overcoming the comparatively inferior electronic conductivity of Na3V2(PO4)3. Based on this, Na3V2(PO4)3/C composites with diverse ratios of citric acid are synthetized via rheological phase reaction way in this work. The consequences display that the Na3V2(PO4)3/C‐1.5 composite brings a higher initial discharge capacity of 113.2 mAh g−1 at a current rate of 1 C with coulombic efficiency above 99% during all cycles. The discharge capacity retains at 117.6 mAh g−1 at the 100th cycle. Even at the high current densities of 5 C and 10 C, the composite also shows superior cycling performance with negligible capacity fading. Its discharge capacities decline from 97 to 92.6 mAh g−1 at 5 C and from 85.3 to 83.7 mAh g−1 at 10 C. These remarkable outcomes arise from its preferable morphology with suitable carbon coating because both excess and skimpy carbon seriously affect the microstructure and electrochemical properties of Na3V2(PO4)3/C composites. [ABSTRACT FROM AUTHOR]