Sodium‐Ion Battery based on an Electrochemically Converted NaFePO4 Cathode and Nanostructured Tin–Carbon Anode

Abstract We report a new sodium‐ion battery formed by coupling a NaFePO 4 cathode and a nanocomposite tin–carbon (Sn–C) sodium‐alloying anode. The NaFePO 4 cathode is obtained by Li–Na conversion of a LiFePO 4 cathode directly in the full cell employing the Sn–C anode and a sodium‐ion electrolyte. The results show that the unique approach adopted here is capable of successfully and efficiently converting LiFePO 4 into NaFePO 4 in a sodium‐ion battery operating at a voltage of 3 V, with a maximum reversible capacity of 150 mAh g −1 , high reversibility, and high rate capability.