Carbon coated Na3V2(PO4)3 as novel electrode material for sodium ion batteries

A Na3V2(PO4)3 sample coated uniformly with a layer of 6 nm carbon has been successfully synthesized by a one-step solid state reaction. This material shows two flat voltage plateaus at 3.4 V vs. Na+/Na and 1.63 V vs. Na+/Na in a nonaqueous sodium cell. When the Na3V2(PO4)3/C sample is tested as a cathode in a voltage range of 2.7–3.8 V vs. Na+/Na, its initial charge and discharge capacities are 98.6 and 93 mAh/g. The capacity retention of 99% can be achieved after 10 cycles. The electrode shows good cycle performance and moderate rate performance. When it is tested as an anode in a voltage range of 1.0–3.0 V vs. Na+/Na, the initial reversible capacity is 66.3 mAh/g and the capacity of 59 mAh/g can be maintained after 50 cycles. These preliminary results indicate that Na3V2(PO4)3/C is a new promising material for sodium ion batteries.

Figure optionsDownload as PowerPoint slideHighlight
► Introduce a new material Na3V2(PO4)3 as both cathode and anode for sodium ion battery.
► A Na3V2(PO4)3 sample coated uniformly with a layer of 6 nm carbon was synthesized.
► Two flat voltage plateaus located at 3.4 and 1.6 V are observed between 1.0 and 3.8 V in a nonaqueous electrolyte solution.
► The electrodes show good cycling performance and moderate rate performance.