Carbon-coated Na 2 FePO 4 F is synthesized by a simple solid-state method with ascorbic acid as carbon source. Structural characterization of Na 2 FePO 4 F by synchrotron X-ray diffraction, scanning/transmission electron microscopy, and Raman spectroscopy reveals that ascorbic acid effectively suppresses the particle growth of Na 2 FePO 4 F, forming the nano-sized carbon coated materials. Electrode performance of Na 2 FePO 4 F for rechargeable sodium batteries is also examined. The carbon-coated Na 2 FePO 4 F sample (1.3wt% carbon) delivers initial discharge capacity of 110 mAh g -1 at a rate of 1/20C (6.2mAg -1 ) with well-defined voltage plateaus at 3.06 and 2.91V vs. Na metal. The sample also shows acceptable capacity retention and rate capability as the positive electrode materials for rechargeable Na batteries, which is operable at room temperature.