Figure 4

Electrochemical performance of the bare and F-doped NVP as cathode materials for half-cell configuration: (a and b) CV curves at different scan rates of NVP and NVP-F _0.15 in the voltage range of 2.8–3.8 V vs. Na⁺/Na: different cycle charge/discharge profiles of (c) NVP and (d) NVP-F _0.15 at 0.1 A g⁻¹; (e) Cycle life tests of prepared bare and doped electrodes at 0.1 A g⁻¹ for 250 cycles and (f) Rate capabilities at different current density.